Undervolting & Overclocking and its effects - AT&T, Rogers, Bell, Telus Samsung Galaxy S III

This a copy of a post from a chip designer, Vikas Mishra, of some 14 years, who has posted this on the Dorimanx xda thread but his statements apply to all kernels.
I think, with his credentials, it is well worth reading this as it explains why u/v'ing and o/c'ing are not necessarily good things and also why one person may, or may not, find a particular kernel/settings are good/bad for their phone/chip...
"Hello people.
Let me introduce myself - my name is Vikas Mishra and I am a chip designer by profession. .
I have worked on critical parts of design of TI OMAP4, OMAP5, Nvidia Tegra 3 etc and have been doing this for the last 14 years.
Of late - I have seen a lot of folks posting BUGS about undervolting of the GPU/CPU.
I think I can explain what are the possible issues with undervolting/overclocking in a laymans language.
It is a little long winded but I think the length is needed for providing the appropriate context.
* What is inside your Cellphone
Your cellphone is an amazing device. It is a full fledged computer
that fits into your pocket. They have all the standard components
that a computer has - except that they are all usually soldered on
the motherboard directly and are not meant to be user-servicable.
The chief components inside your cellphone are
1. Application Processor (AP)- this is the heart of a modern
cellphone. These are manufactured by many companies - the main
ones are Qualcomm, Nvidia, Samsung and Apple. The other not so
well known ones are made by Texas Instruments, ST Ericsson,
Marvell and Broadcom.
A modern AP has logic to control the camera and process the image
that it generates, to do video encoding (video recording) and
video decoding (movie watching), Audio processor etc. in addition
to the well known CPU and GPU.
2. Power Management Controller - This is the chip that is
responsible for generating and regulating the voltages that are
used by all the components on the board.
3. DRAM - not very different from the DRAM found on a PC (except
that it is lower voltage)
4. Flash - for storage
5. Touchscreen controller
6. Logic for microphone, speaker
7. Battery
One of the most complex piece of circuitry on the phone is the AP
and the power management controller.
* Circuit Basics
A modern AP has millions of circuit units called (Flip
Flops). These flip flops have two parameters associated with them
called Setup time and Hold time. More details on what a flip flop
can be found on the wikipedia at
http://en.wikipedia.org/wiki/Flip-flop_(electronics) . This is a
nice bit of bedside reading if you are interested.
A setup time roughly indicates what frequency you can run a design
or an AP at before it becomes unstable.
A hold time roughly indicates the maximum voltage till which a
design is stable.
A fully technical analysis of what is involved in these timing
parameters requires a degree in electrical engineering but in broad
terms the problem is described below.
Chip designers diligently ensure that all of the millions of the
flip flops in a chip meet the setup and hold time across a broad
range of voltages and silicon parameters. They do a pessimistic
analysis to ensure that a chip will run reliably across a wide
range of voltage/frequency combinations.
However, contrary to the popular belief, chips vary widely in their
silicon parameters. Even chips on a the same wafer and different
flip-flops within the same chip can have widely different silicon
parameters. This is why what works on one particular chip will not
work on the other chip.
Your silicon manufacturer provides a range of voltages and
frequencies across which the device can work reliably. The phone
manufacturer will further narrow down the range depending on the
other components they choose within the phone board.
* How does voltage affect the design
Reducing voltage makes the design slower and increasing voltage
makes the design faster.
So can I keep on increasing the voltage for ever and make the
circuit faster and faster. The answer is no - a point will come when
the circuit will become unreliable. This becomes unreliable because
the "hold time" of one or more of the flops will start
violating.
As you reduce the voltage of the design, the circuit will start
becoming slower. However typically it will continue to work till at
apoint it starts failing - this failure occurs due to violation of
"setup time" of one or more flops in the design.
So what happens when the setup time or the hold time of a design
fails - the answer is that it is unpredictable. Meaning suddenly if
you ask the processor what is the value of 2+2, the answer it will
provide could be unreliable - in some cases it could be 3, in some
cases it could be 4 in some cases it could be -2349783297 (a random number).
I am of course oversimplifying but I hope you get the picture.
* How does undervolting affect your phone processor
The reason undervolting is so appealing to people because they
thing that undervolting will save power and improve battery
life. While this is true in theory, in practice there is a caveat.
It will reduce the power of the chip, but the power consumed by the
phone as a whole will not improve. In some cases in fact it can
deteriorate. Let me explain.
The most power hungry part in the phone is not the AP - it is the
LCD screen. All of these screens consume a ton of power. So even
though your AP is now consuming lesser power, the overall impact to
the phone as a whole is not that much.
If you accompany undervolting with a frequency reduction (which you
should), the total time taken for doing a web page rendering (for
example) would increase. During this time the screen is on and it
has more than compensated for the power that you saved in the
AP.
You could of course come up with examples where this wouldn't
happen - but on a whole, IMHO, you should leave the voltage of the
AP/GPU/CPU to the guys who know the system best - the guys who
designed the chip and people who manufactured it.
* How does overvolting/overclocking affect your phone processor
If you want that last drop of performance from your phone and you
over clock it, at a point some of the design flops will start
violating the hold time and the design will stop working reliably.
Again, in some anecdotal cases this would work - but this is not a
reliable means/mode of working. Just because your friend's or your
first cousin's girlfriend's phone works - doesn't mean yours will
work as well.
* What are the user observable impacts of undervolting/overclocking?
It is hard to say - simply because there are so many of flops in
the design.
In some cases - you wouldn't see anything wrong with the phone
until one day you do. In some cases it will result in a SOD
immediately. In some cases it will result in your phone not waking
up reliably.
IMHO the risks of issues with undervolting/overclocking far
outweighthe potential gains you may get out of it. Usually there
is no lasting damage to the phone/AP if you overlock/undervolt but
it is possible to do it. For example, You run the phone at such a
high frequency that the chip temperature becomes more than what it
was designed for and the Silicon just fails.
So "Just say No" . Don't overclock or undervolt your phone -
leave it to the guys who really understand what they are doing.
>>≥>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
I'm curious on what you guys think about all of this.
As for me I currently have a need for undervolting with heat issues. So I'll just take this with a grain of salt.
AT&T SGS3 Marble White
Team AoCP 4.6 The Collective ROM
Medical Marijuana Supporter

Dude knows what he's talking about. However...
Most of what he wrote pertains mostly to the extreme ends of the OC/UV spectrum. I didn't see much that suggested that light OC/UV has any potential risk, and it shouldn't: phone processors are generally underclocked to start with for battery, stability, or reliability reasons; processors voltages are selected with a certain tolerance for material defects that require higher voltage. For the most part, practical limits and common sense keep us from undervolting a processor until it won't boot, or overclocking until the battery explodes.
The post is definitely worth reading and should be enlightening for many readers. It should be taken with a grain of salt though: IIRC our processors are supposed to run stably at 1.7GHz @ 1050mV (I have no idea where my citation for this went, so consider it to be completely made up ), but we don't run them like that.
He glossed over an interesting point: underclocking and/or running a conservative governor might draw more power by keeping the screen on while execution is happening. It's an interesting consideration that would have countered his other points if fully explored. I see a lot of people posting that their 2.1GHz overclock still manages to get great battery life, and I can't help but wonder whether having the extra grunt when needed is working to their advantage. I'm totally off-topic though, so I'll shut up.

His priorities are all off. He is looking at it as a hardware engineer and not a user. All we are worried about is extra performance, enough stability that we can't tell the odd hiccup from all the software bugs we hit, and long life from the hardware. If my CPU makes a bug in a game, its not the end of the world, if it starts to irritate me I can reduce the clocks a bit. He makes it out as though it is an inevitability, that is not true. It is also not a degrading situation. It does not hurt the hardware to make an error and once you are past the maximum stable speed for your voltage they produce them at random with the frequency depending on how far past the limit you are. Also, the ideal overclock produces ZERO errors and only reduces chip life span in sofar as it is able to do more work over a shorter period of time. Most chips have quite a bit of headroom even at the stock voltage before they start producing any errors at all. My phone has been running for months at 1.9ghz, if there have been any errors they were indiscernible from software errors. My desktop has been running at a 60% overclock for 3 year, when tested it can run for days at full load without any errors.
As for overheating the chip, a little common sense goes a long way there and its going to be pretty hard to do without a poor hardware design or increased voltages. Personally I limit my cell phone overclocking to the highest speeds I can achieve without increasing the stock voltage because I have no way to monitor the temperature and do not know if there are thermal protections built in.

Related

How safe is overclocking and how does it affect battery life.

Hey there people. I'll be receiving my artemis tomorrow and I would like to get the most out of it. I allready decided on what rom I am going to use. but I want to know how safe is overclocking. I want my artemis to be able to watch movies without to many trouble. I want to play some games (Age of empires, myst, some of those games) and more. I am willing to charge my artemis every night as long as I can do the entertainment as much as I want
So advice please people. To what could I safely overclock and how long will my battery last then?
Mines currently overclocked to 286MHz and has been since I had it (over 8 months usage now). The battery lasts for well over 4 days without a charge with moderate usage but obviously the more calls etc then the quicker it'll go down. Its device dependent but mine physically won't overclok any higher. If I try then it immediately freezes but 286 is spot on with no issues at all. I've known others who couldn't go quite as high but like I've said previously, it depends on your device so give it a bash.
Yeah but it won't be wise to blow my mobile up the first day
Nobody will tell you what is "safe CPU frequency" for overclocking, but I never heard about Artemis owner who damaged device by going to far. I tried about 270 MHz with my PDA for long time, with higher freq. I had to soft reset device, one even hard reset was necessary, but after that everything was working OK. Remember not to set overclocking after reset
Regarding battery drain - I didn't made tests, but with BatteryStatus and "on-demand" overclocking I noticed no big difference - when you play game CPU is oveclocked, but then it may by underclocked.
How safe is overclocking and how does it affect battery life
Hi,
a popular formula to calculate the dynamic power consuption of CMOS ICs is:
P = (1/2)*C*V^2*f (C - Capacitance, V - Supply Voltage, f - Frequency)
As you can see, the frequency is a linear factor in this equation. So if you double the clock frequency, the power dissipation will also double. But the processor does only has a portion of the total power dissipation of your device. So the battery "life time" will not be doubled.
If you choose a frequency that is to high, the device will not work correctly -> bit-errors -> Softreset. This is not serious, but my concern about extreme overclocking are the extrem temperature cycles -> produces a mechanical mismatch -> mechanical failure inside the processor package or printed circuit board. But this is a long term process.
Kind regards,
hqqh

[Q] overclock dameges hardware but does it damage device or just battery

overclock dameges hardware but does it damage device or just battery
The Hardware is the Device or the battery....
every thing you can touch is hardware :3
I've never overclocked a phone from myself... Unfortunately previous experiences with PC overclocking have ended badly with a lot of components breaking, if you know what your doing, I've found the results can be more than worth the risk!
Overclocking your phone will put more stress on your hardware, CPU will attempt to run more bits of information than it's designed for, battery will be pushing out more power to keep up with hardware demand, etc...etc...
Computers are easier to handle in terms of overclocking because you can modify hardware such as liquid cooling or bigger fans to support the extra heat generated from your adjustments. The strain on the hardware will always be there but it's easier to manage than portable devices. Phones on the other hand are restricted in terms of cooling; you may notice a larger amount of heat generated when you're playing games or running Google Maps. In most cases, always remember that heat = bad in terms of most things technology related... Unless it's a toaster oven.
I had a Motorola Droid for over 2 years (before my SE switch) and I had overclocked it to around the 1GHz marker (550MHz stock), the only thing that kept my Droid from blowing up was using a Ultra Low Voltage Kernel and Memory Management. While that may seem reassuring I know in the back of my head that I'm still cutting away at the overall life cycle of my hardware. My phone would heat up anytime I had to travel with GPS and that only reminded me that my phone would explode at any moment... Well, not really explode but that would've been a cool experience.
It's your choice to overclock your phone or not, just keep in mind that even while using a LV Kernel and managing your memory the stress on the CPU, Battery, and RAM is there. (I personally believe) Hardware now-a-days can handle the stress and most likely you'll be getting a new phone in 2-3 years time anyway.
n0_face said:
Overclocking your phone will put more stress on your hardware, CPU will attempt to run more bits of information than it's designed for, battery will be pushing out more power to keep up with hardware demand, etc...etc...
Computers are easier to handle in terms of overclocking because you can modify hardware such as liquid cooling or bigger fans to support the extra heat generated from your adjustments. The strain on the hardware will always be there but it's easier to manage than portable devices. Phones on the other hand are restricted in terms of cooling; you may notice a larger amount of heat generated when you're playing games or running Google Maps. In most cases, always remember that heat = bad in terms of most things technology related... Unless it's a toaster oven.
I had a Motorola Droid for over 2 years (before my SE switch) and I had overclocked it to around the 1GHz marker (550MHz stock), the only thing that kept my Droid from blowing up was using a Ultra Low Voltage Kernel and Memory Management. While that may seem reassuring I know in the back of my head that I'm still cutting away at the overall life cycle of my hardware. My phone would heat up anytime I had to travel with GPS and that only reminded me that my phone would explode at any moment... Well, not really explode but that would've been a cool experience.
It's your choice to overclock your phone or not, just keep in mind that even while using a LV Kernel and managing your memory the stress on the CPU, Battery, and RAM is there. (I personally believe) Hardware now-a-days can handle the stress and most likely you'll be getting a new phone in 2-3 years time anyway.
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The life cycle on phones today is far longer then you would expect. Every processor can handle more speed then the manufacturer clocked it at but they will never release a device with a processor at its full potential. Unless your taking your xperia play and o/c to constant 2ghz you really will never see a degrade in its life. Even o/c'ed the phone will outlast a 2 yr contract.
I recently went back to my OG Droid because my Xplay is torn apart. My droid is 125 min - 1300 max and had the device for 3 years. It have always used the 125 -1300 max with regular voltage with no profiles, yes if your o/c and using navigation its gonna heat up, the droid heats up at 550mhz on navigation with stock kernel , but then again when navigating I would always underclock to keep the heat down. It was never gonna blow up and it will run another few years im sure, its a trustworthy backup !
With all the phones I've had , never had a problem with overclocking , no damage to device or battery, except reboots if clocked to high or reboots if not enough voltage (every device and processor are different though, even the ones with same make and model) which is why you should still be careful, you could get a device that just won't like anything you do to it, but I've never had that problem
it really depends how much you overclock it. most cpus are underclocked especially in phones for battery life reasons. ive been running by pc at about 130% for two years with no issues. now if you double the speed 2ghz (1.9Ghz doomlord kernel) that would mess up you device super fast lol

How to undervolt and get better battery life. Please post your results and how to.

Hey all, this is a thread I saw on different forum and think it is would be good for noobs like myself to benefit from. How to undervolt your CPU and also post your Galaxy Note 2 specific results. I have tried these next steps, and so far I'm doing okay (can't give an accurate results on battery life yet). Like I said (I'm not ashamed to say I'm a noob) but if others can throw their two cents in, we can all learn and this thread can be useful. The next part was cut and paste d from other forum. And I deleted the url for the kernel and root
Prerequisites:
1. Must be rooted and recommended kernel
2. Download and install System Tuner
3. Download and install Stability Test
Steps:
1. Open System Tuner and select CPU
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
2. Drag the slider shown in the picture to overclock or underclock CPU. In this picture we are overclocking to 1.8ghz
3. Select Voltage at the top to get to CPU voltage settings.
4. Ok, here select the buttons as they are in the picture.
a. Select the Green circled button to save current stock default settings.
b. Select the Yellow circled button 4 times exactly to reduce the millivolts by 100.
Stability Testing:
Now we really should make sure that it can handle it under load right? :silly:
1. Open Stability Test and select CPU+GPU Stability Test.
2. Select Full Details - Proceed.
3. The app will now start stressing your cores. I waited until at least 10 cpu passes before quiting the app...
Cliffnotes:
-By default, your settings will revert back after you restart your phone. You can set them to load at boot, but don't do this unless your absolutely sure that they're stable!
Open System Tuner - CPU - Menu key - Settings - Active Tweaks - Reapply CPU Settings - On Boot Completed
-Whenever i tried to lower the mv more than 100 below stock at 1.8ghz, my phone rebooted
-I am in no way responsible for anything that might happen after performing the above, even if you start your sentence with the word "but"
-here's stock settings in case you need to revert
[/QUOTE]
This is an interesting project but I would think that the average user would not need this as battery life is pretty good. Speaking for myself, I am able to get through the whole day without any issues.
Of course there might be other reasons why someone would want to do this.
Doc
Thanks
Sent from my SGH-I777 using xda premium
DocEsq said:
This is an interesting project but I would think that the average user would not need this as battery life is pretty good. Speaking for myself, I am able to get through the whole day without any issues.
Of course there might be other reasons why someone would want to do this.
Doc
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Click to collapse
from what i've read, undervolting save very little battery time as the processors are pretty efficient anyways. i don't have actual numbers, but i'd guess you'd get a few extra minutes - which some may really need.
it's that freaking gargantuan screen that sucks the most juice. there used to be a mod to undervolt displays. they had it working on an OG galaxy tab. i never really seen it used anywhere else.
I have an international version of galaxy note 2. I'm currently using AllianceROM and Perseus kernel. And my stock voltage is way way higher than yours. Like 1400mV mine, 913mV yours. Can I undervolt my note 2 to same specifications like yours? Thanks.
This is interesting but setcpu when I had it on my last phone worked awesome and was very easy to use.
Sent from my Amazing Galaxy Note 2!
rjisanandres said:
I have an international version of galaxy note 2. I'm currently using AllianceROM and Perseus kernel. And my stock voltage is way way higher than yours. Like 1400mV mine, 913mV yours. Can I undervolt my note 2 to same specifications like yours? Thanks.
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Click to collapse
You is 1400 mV on 200 MHz? It's probabky 1400 on 1.6 ghz.
Sent from my SCH-I535 using xda premium
I also have Perseus kernel overclocked but still have great battery life. Thanks for the tip though might try it and compare the difference just in case.
I agree with DocEsq.. It is interesting indeed, but is it really necessary?
Can you overclock it?
My note 2 seems to be charging forever after undervolting. I'm talking for about 6-7hrs charging time here. What seems to be the problem? I'm using Perseus kernel. TIA!
Sent from my GT-N7100 using Tapatalk 2
I once conducted a test with my evo3d. I basically ran an amp meter inline with the battery. Measuring the exact power consumption. I dont remember the exact specs, but undervolting and underclocking my phone compared to stock made a very minute difference in actual power consumption. A difference of about 8-15ma. This was during a CPU full load scenario for about 10 seconds. Even loading the CPU with the screen off to take as many variables out as possible it was very little difference. During normal operarion the power consumed was virtually identical.
So the 2 to 3% of the day (overall time) your phone is actually under HEAVY load, it won't make much difference. It did make a performance impact. So not much benefit, just reduced performance.
Now overclocking and/or overvolting did make a larger difference in consumption at high constant load.
Want to ACTUALLY make a large impact on your battery life? Make sure you don't have any apps preventing your phone from sleeping and run the absolute lowest screen brightness you can stand.
YMMV.
Sent from my Galaxy Note 2 using Tapatalk 2
The benefit I found from undervolting isn't better battery life, it's reduced heat which in heavy use provides better performance due to no cpu throttling. I'm running 1800mhz using less battery than 1600mhz and with same temps as stock. Very stable, been running this for a month now at least.
Action B said:
The benefit I found from undervolting isn't better battery life, it's reduced heat which in heavy use provides better performance due to no cpu throttling. I'm running 1800mhz using less battery than 1600mhz and with same temps as stock. Very stable, been running this for a month now at least.
Click to expand...
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What app did you use to undervolt?
Sent from my Amazing Galaxy Note 2!
yankees45us said:
What app did you use to undervolt?
Sent from my Amazing Galaxy Note 2!
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Click to collapse
I'm using the stweaks app that comes with perseus kernel.. I've undervolted quite a bit and I get better battery life.. Still not quite as good as I had stock, but definitely a lot better for being over clocked.. I just reduce each level to the level below it and run for a few to check stability and keep going from there.. So far I have had no trouble at all with undervolting.. Certainly nothing like I did with my elte.. Here's where I've been for almost a week as well as today's battery results so far with Pandora playing over 3 hours straight and moderate use..
Sent from my SPH-L900 using Tapatalk 2
Yeah, just to let you know that there certainly isn't a linear correlation between undervolting and underclocking and power usage. That might have been the case in simpler times, but with modern multi-core microprocessors, you might actually be decreasing battery life by screwing with your clock rate or voltage. Yes, the defaults err on the side of caution, but it's a whole lot of work for little to no gain.
For example, by reducing your phone's clock rate, you might actually be forcing your phone to be spending more time at load; thereby not allowing it to fallback to its sleep state. There is also something called the power wall, where an increase in operating frequency requires an exponential increase in power. However, the reverse is also true. It can be counter-intuitive to think of it this way, so a practical example is how on a 100 mile trip, a 25 mpg sedan saves 4 gallons of gasoline over a 12.5 mpg SUV. However, over the same distance a 50 mpg hybrid saves only 2 gallons over the 25 mpg car. By that same logic, a mythical 100 mpg vehicle would only save 1 gallon of fuel. It's the law of diminishing returns. Then of course, there are the stability issues that you should take into account.
There is a lot that happens behind the scenes regarding power management. Your phone is capable of intelligently scaling it's processors, voltages, and frequencies up or down all based on current and expected demand. There are people who spend a lot more time doing this for a living, and the idea that you can do it better is probably a falsehood. If you want MOAR POWER, by all means overclock/overvolt it (just don't fry it), but trying to get an extra couple minutes of run time is likely a waste of some hard work. It's the software that kills your battery, not the hardware.
Talking about computer architecture can be complicated and boring, but start with searches on "rise time" and "logic level transitions" if you want to want more background.
Action B said:
The benefit I found from undervolting isn't better battery life, it's reduced heat which in heavy use provides better performance due to no cpu throttling. I'm running 1800mhz using less battery than 1600mhz and with same temps as stock. Very stable, been running this for a month now at least.
Click to expand...
Click to collapse
Interesting... whenever I'm dling using a torrent client my phone gets a nasty fever and I've gotta set it down somewhere as it will literally make me sweat, lol. I do b there think I'll be undervolting just for that specific circumstance but that is a very interesting concept...
anishannayya said:
Yeah, just to let you know that there certainly isn't a linear correlation between undervolting and underclocking and power usage. That might have been the case in simpler times, but with modern multi-core microprocessors, you might actually be decreasing battery life by screwing with your clock rate or voltage. Yes, the defaults err on the side of caution, but it's a whole lot of work for little to no gain.
For example, by reducing your phone's clock rate, you might actually be forcing your phone to be spending more time at load; thereby not allowing it to fallback to its sleep state. There is also something called the power wall, where an increase in operating frequency requires an exponential increase in power. However, the reverse is also true. It can be counter-intuitive to think of it this way, so a practical example is how on a 100 mile trip, a 25 mpg sedan saves 4 gallons of gasoline over a 12.5 mpg SUV. However, over the same distance a 50 mpg hybrid saves only 2 gallons over the 25 mpg car. By that same logic, a mythical 100 mpg vehicle would only save 1 gallon of fuel. It's the law of diminishing returns. Then of course, there are the stability issues that you should take into account.
There is a lot that happens behind the scenes regarding power management. Your phone is capable of intelligently scaling it's processors, voltages, and frequencies up or down all based on current and expected demand. There are people who spend a lot more time doing this for a living, and the idea that you can do it better is probably a falsehood. If you want MOAR POWER, by all means overclock/overvolt it (just don't fry it), but trying to get an extra couple minutes of run time is likely a waste of some hard work. It's the software that kills your battery, not the hardware.
Talking about computer architecture can be complicated and boring, but start with searches on "rise time" and "logic level transitions" if you want to want more background.
Click to expand...
Click to collapse
Like the way you put that. Good analogies there it just seems like the other day that undervolting was the hip thing to do. Technology just moves at such a wonderful pace though. Just one little FYI though, since i do like you analogy i would like to point out that the law of diminishing returns actually refers to something else entirely. I know, I know, nitpicking, but it's just that everyone is always off the mark with that one and, well I guess I'm just an anal ahole (and an economics major, ,which I guess just overall makes me an a hole, ,lol)
If you have ever pulled apart a laptop and saw how much thermal paste the engineers at the factory "designed" for their to be on there, or seen the air/fuel ratio most cars roll off the lot with, or ever replaced an intake in a vehicle with a high performance unit I'm not sure you would feel the same way about you yourself not being to do a better job.
I get the point, and I believe often there is validity to that point, but sometime things just aren't that simple. This is where power gains come from in tuning a car (which i do). This is where efficiency is raised by removing restrictive components in a vehicle (intake, exhaust, etc) and where cooling performance is increased on a CPU with the proper application of a quality thermal paste.
Whenever time is money, and you are deciding between your bottom line and something that works and something that works as well as it can, shortcuts are made and corners are cut. Perhaps they could have spent another 200 hours for the team to absolutely optimize the processor for each device, but the cost would have been an additional $20,000 dollars. This is not always the case, but with processors I think it is. I will undervolt everytime and I do take objective measures for battery and I agree gains are relatively small. For cooling, I found the difference to be very significant at 1800, mhzI didn't check at 1600mhz, however. I can run a full Antutu benchmark as much as I want at room temperature and never exceed the throttling point (70 C if i remember correctly). Now, I am in no way saying these are facts, these are opinions, so I could be wrong of course.
Psychotic-Cerebellum said:
Interesting... whenever I'm dling using a torrent client my phone gets a nasty fever and I've gotta set it down somewhere as it will literally make me sweat, lol. I do b there think I'll be undervolting just for that specific circumstance but that is a very interesting concept...
Like the way you put that. Good analogies there it just seems like the other day that undervolting was the hip thing to do. Technology just moves at such a wonderful pace though. Just one little FYI though, since i do like you analogy i would like to point out that the law of diminishing returns actually refers to something else entirely. I know, I know, nitpicking, but it's just that everyone is always off the mark with that one and, well I guess I'm just an anal ahole (and an economics major, ,which I guess just overall makes me an a hole, ,lol)
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Click to collapse
The TIM wasn't put on there by the engineers who designed the chips; they are put there by workers being paid next to nothing.
Your phone doesn't have a CPU, it doesn't even use thermal paste; it's usually just a rubber contact patch and passive heat dissipation. This actually brings another point where overclocking can sometimes reduce performance due to throttling by thermal constraints (why our phone has such a low GPU rate than what it is capable of in other phones with better thermal envelopes).
You aren't replacing the SoC, you are changing the software that determines how to set the voltage/clock multiplier. The car analogy isn't valid.
And I stand corrected regarding the Law of Diminishing Returns; never paid attention in macro-econ. I think was because my prof. was more interested in forcing his political ideology upon us than actually teaching the subject. :silly:
EDIT: Keep in mind, the engineers rarely get what they want. The product the consumer ends up getting is usually dictated through a collaboration of what the business and marketing teams want. The engineer might request a large cooler clamp with a perfectly lapped surface and a carbon-based TIM. In reality, the consumer gets a dinky fan with melt-on TIM and retention springs. Money talks.
anishannayya said:
The TIM wasn't put on there by the engineers who designed the chips; they are put there by workers being paid next to nothing.
Your phone doesn't have a CPU, it doesn't even use thermal paste; it's usually just a rubber contact patch and passive heat dissipation. This actually brings another point where overclocking can sometimes reduce performance due to throttling by thermal constraints (why our phone has such a low GPU rate than what it is capable of in other phones with better thermal envelopes).
You aren't replacing the SoC, you are changing the software that determines how to set the voltage/clock multiplier. The car analogy isn't valid.
And I stand corrected regarding the Law of Diminishing Returns; never paid attention in macro-econ. I think was because my prof. was more interested in forcing his political ideology upon us than actually teaching the subject. :silly:
EDIT: Keep in mind, the engineers rarely get what they want. The product the consumer ends up getting is usually dictated through a collaboration of what the business and marketing teams want. The engineer might request a large cooler clamp with a perfectly lapped surface and a carbon-based TIM. In reality, the consumer gets a dinky fan with melt-on TIM and retention springs. Money talks.
Click to expand...
Click to collapse
1. The voltages are set by an engineer, that is what I was referring to.
2. The CPU thing was an analogy as was the car. Not a direct comparison. The analogy is referring to how there is set fuel and timing tables just like there is set voltage tables, both might not be the most efficient from the factory, tweaking them can improve things. How is this completely not valid?

Cooling mods [hardware]

Hi all!
I have been noticing that the tablet can get fairly hot where the CPU is, and under load it can reach fairly high temperatures - CPU prime got it up to over 90°C for me to the extent that I had to shut it down.
To be honest, it doesn't really impede normal usage, and normally it seems to reach slightly over 70°C under higher workloads. I suppose that's not unheard of for ARM devices and might not actually count as overheating. But after seeing this video on the Teclast X98 Pro and some other info on modding in tablets, I was still wondering if there'd be a way to improve the cooling on the Note 10.1 2014 to get lower average temperatures - potentially, that should also lead to more stable and fluid running under high loads, as there won't be any need for throttling, and it might also be good for the components to keep temps lower.
So I guess my main question is if anyone has undertaken anything of this sort for this or comparable tablets? @thebadwrench has recently posted a very useful guide about swapping the battery with a rare shot of the inside of the tablet: http://forum.xda-developers.com/showpost.php?p=66124495&postcount=13
I was thinking what the most sensible way could be to improve cooling of the CPU, which should be the small shielded unit in the lower centre of the second picture. People seem to have had good results with copper, but it seems fairly crowded in there and it might be hard to get it installed without shortening anything.
Aside of the more practical question, I'd also be interested in the typical temperature that other people's tablet reaches and if you have any better apps than CPU prime to produce high CPU load - possibly one that shows CPU temperature at the same time as well? Currently, I'm having another app running to check CPU temp (CPU prime for some reason only shows the battery temp).
Looking forward to everyone's answers!
PS: @mods Not sure if this is the right section of the forum, feel free to move if you feel it fits better elsewhere.
AFAIK Microsoft intended to fit an innovative kind of heat sink into their Lumia 950 and finally produced a standard design w/o particular cooling devices due to difficulties.
I have no clue how anything could be done. Except replacing the back cover with something thicker, offering room for heatsinks, fans, peltier elements or such.
But the Note should at least have thermal throttling and emergency shutdown features, like all current phones, which will throttle within the first half minute under full load.
franzli said:
Hi all!
I have been noticing that the tablet can get fairly hot where the CPU is, and under load it can reach fairly high temperatures - CPU prime got it up to over 90°C for me to the extent that I had to shut it down.
To be honest, it doesn't really impede normal usage, and normally it seems to reach slightly over 70°C under higher workloads. I suppose that's not unheard of for ARM devices and might not actually count as overheating. But after seeing this video on the Teclast X98 Pro and some other info on modding in tablets, I was still wondering if there'd be a way to improve the cooling on the Note 10.1 2014 to get lower average temperatures - potentially, that should also lead to more stable and fluid running under high loads, as there won't be any need for throttling, and it might also be good for the components to keep temps lower.
So I guess my main question is if anyone has undertaken anything of this sort for this or comparable tablets? @thebadwrench has recently posted a very useful guide about swapping the battery with a rare shot of the inside of the tablet: http://forum.xda-developers.com/showpost.php?p=66124495&postcount=13
I was thinking what the most sensible way could be to improve cooling of the CPU, which should be the small shielded unit in the lower centre of the second picture. People seem to have had good results with copper, but it seems fairly crowded in there and it might be hard to get it installed without shortening anything.
Aside of the more practical question, I'd also be interested in the typical temperature that other people's tablet reaches and if you have any better apps than CPU prime to produce high CPU load - possibly one that shows CPU temperature at the same time as well? Currently, I'm having another app running to check CPU temp (CPU prime for some reason only shows the battery temp).
Looking forward to everyone's answers!
PS: @mods Not sure if this is the right section of the forum, feel free to move if you feel it fits better elsewhere.
Click to expand...
Click to collapse
Similar temperatures are note uncommon in mine. One suggestion is to use a small desktop fan and aim it down at the tablet when your demanding alot from the cpu. I sometimes do that with mine and it actually brings the temperature down about 15 degrees. Its not a mod, but it does work
Thanks for your answers so far!
@lecorbusier yes, I suspect it has throttling, but in the interest of better running it would be nice to avoid throttling when possible. I'm not sure about the effect on battery life - throttling might be good in that a reduced frequency might need less energy, but running hot in the first place is probably bad for battery life.
In fact, part of my problem might stem from either the ROM or some apps I am running - Squid on temasek's CM13. Maybe I just never noticed this before, or didn't use squid so often, but I've noticed that the last couple of days CPU gets up to over 70°C at times with just some writing in squid. Not sure if this is normal, will probably post it in the CM13 thread. But my general idea/wish to improve cooling still stands independently of that.
Similar temperatures are note uncommon in mine. One suggestion is to use a small desktop fan and aim it down at the tablet when your demanding alot from the cpu. I sometimes do that with mine and it actually brings the temperature down about 15 degrees. Its not a mod, but it does work
Click to expand...
Click to collapse
That sounds like an effective method (and I guess in a way one might call it a mod ). I'm thinking about something more portable, and hence passive though.
I will probably try opening up and having a look at the current cooling mechanism to see if adding a copper shim or a better silicone heat sink etc. might help things. Another consideration would be a modded case that contains some metal instead of plastic on the back side. That might help to take away some of the heat even though the plastic back of the device itself probably remains a poor heat conductor. Might be a complicated mod, but I'll see if I can come up with a way to do that. If/when I manage to get something done, or some new thoughts, I will advise here.
Any further input of course still very welcome!
Metal will disturb the various antennas.
A back cover replacement containing one or two fans, adding 1 to 2cms of thickness, and draining the battery with the fans while looking clumsy, thats the "best" solution I could imagine.
Or a back cover replacement containing one or two copper plates, cut and arranged in a way that the antennas aren't too handicapped. Probably you have to remove the various EMI shields to be able to establish direct contact between the chipset and the plates. That is, if the chips don't have contact with the shield plates.
I think this will be something never been done before, but probably after.
Like the battery mod for phones, where you solder one battery together with a second one and cut a hole in the back cover, that the now double-thick battery may fit. That's already been done.
Good point about the antennae, I hadn't thought about that! That also makes sense of the lack of metal cases (facepalm). Might still try modding a case with some metal in some spots at some points, but good to keep in mind how this might impact wifi and bluetooth.
My plan was to see if there'd be a chance to fit some slim copper plates in strategic position on top of the CPU inside the normal case. I'll have to open it up and see how much, if any, space there is - but will probably try this first on a Galaxy Tab S 8.4 that I rely on less for productivity (and that does actually get way to hot, to the point of self-shutdown). Whenever I find the time that is...
Will report when I get around to doing anything on the Note (and might open a topic at the Tab S forum in case I do try a mod there first).
I added a copper shim for cooling to my Galaxy Tab S (will put a more detailed post on that forum when I find some time), which seems to have helped to control temperatures somewhat better. I had two odd crashes, but had some before I did the mod, so am relatively confident that's a problem of the ROM rather than my mod.
Will probably try it on my Note as well soon and report here for anyone who might be interested.
Have modded my Note now, and am planning to post a more detailed description some time (won't have time before next month though). It had clearly improved temperatures and stability of my Tab S, but I'm not sure how much of a difference it made on the Note 10.1 2014 because I didn't measure the baseline temperatures before the mod right (used CPU Prime benchmark which seems to have general stability issues on the temasek ROM I'm using).
Currently, I have idle temperatures of around 30C, under normal use it would get to 40-50C, and under stress (app StabilityTest) it goes up to around 89/90C after 5min and to 92/93C after 10min.
I'd be quite interested in what temperatures other people get on their devices without any modification?
franzli said:
Have modded my Note now, and am planning to post a more detailed description some time (won't have time before next month though). It had clearly improved temperatures and stability of my Tab S, but I'm not sure how much of a difference it made on the Note 10.1 2014 because I didn't measure the baseline temperatures before the mod right (used CPU Prime benchmark which seems to have general stability issues on the temasek ROM I'm using).
Currently, I have idle temperatures of around 30C, under normal use it would get to 40-50C, and under stress (app StabilityTest) it goes up to around 89/90C after 5min and to 92/93C after 10min.
I'd be quite interested in what temperatures other people get on their devices without any modification?
Click to expand...
Click to collapse
Thanks for the update. I did some baseline checks for you, using the same StabilityTest app for consistancy purposes. I am also on temaseks build, cm13 more specifically. I run temaseks 12.1 build just as often as the cm13, so I will run the tests there as well. I revert back to my stock rooted kitkat rom about 1 or 2 days per week so I'll check the temps on that ROM as well.
So, at idle I'm a little warmer than you, hovering between 37C and 40C. Under normal use (like web browsing) I'm between 50C and no higher than 57C. Under stress (again, using same app) I was at 90C at 5 minutes and 91C after 10 minutes. So slightly warmer on low end, nearly identical on the big end. I have the samsung flip cover thats specifically made to fit the 2014 edition on mine, so that could account for my slightly warmer temps. Its worth noting that when gaming on a VERY cpu demanding game, I never reach anything above 78C. Its probably one of the top 10 most cpu demanding games on play store and BY FAR the most I ever demand from my CPU, consuming a whooping 1.5-2Gb of RAM at times.
I'll check the numbers on my other 2 normally used ROMs here in the next few hours and I'll post those results too :good:
On a side note, my galaxy s6 phone (completely stock, near new) averages nearly indentical cpu temps and after researching the matter on it, I found that those temps (on the s6) are what others are getting as well. So it seems that, generally speaking, samsungs might just run with warmer temperatures. I did see somewhere that 100C is kinda the 'YIKES!' point for them and that they start clocking down around that temp to prevent permanent damage
franzli said:
I'd be quite interested in what temperatures other people get on their devices without any modification?
Click to expand...
Click to collapse
Ok, I've done some testing with a few different ROMs and I think you might be as susprised with the results as I am. First of all I need to correct myself in my last post. The initial testing I did was on temaseks unofficial CM12.1 build, not on the CM13 build. I have now tested on temaseks cm 12.1 and cm13 builds, my stock rooted & debloated 4.4.2 ROM and an old nandroid backup I have of hyperdrives 4.4.2 ROM. Heres what I found...
Temaseks CM13 build ran the hottest and was by far the most stressful on the processors and therefore ran the hottest. It consistantly kept the CPU clocked at near max (even when set to "ondemand"), whether needed or not (with no background process running) and would only reduce power when forced via CPU governor or was at the safety threshold for temperature, which I can now comfortably say is about 95C. Tablet was slightly warm to the touch at idle with a temperature of between 50C & 55C. Under moderate load temperature jumped very raidly to the mid 80C range and then would stay there pretty steadily. Under heavy load, CPU temp quickly peaked at 94C where while watching the CPU output, it was obvious the CPUs were going in & out of protection mode as they would drop to 1600MHz, then peak at 1900MHz, 1600MHz, 1900MHz & repeat this. I didnt let this go on for more than about 2 min before shutting down and allowing tablet to cool.
Next, I repeated tests on both touchwiz based kitkat ROMs I have backups for. 1 of them is stock, rooted, debloated and un"tweaked". The other is stock, rooted, debloated and tweaked. Both ran MUCH cooler, peaking at 80C & 82C. These were ocassional spikes and actually averaged around 75C when under heavy load. Now comes the good news...
I have identified a major contributor of excessive CPU temps. When testing on the touchwiz ROMs and observing CPU clocking in relation to CPU temps, I found that the governors are set lower in these touchwiz ROMs. They were a steady 1300MHz with the occasional 1600MHz spike. They averaged 55C to 63C under moderate load and when under heavy load never reached more than 82C.
So, I am now back on my long time daily driver, temaseks cm12. 1 build and I'm ditching the CM13 build entirely. At least for now. I have set my CPU governors down to 1300MHz and with heavy load for nearly 30 minutes (gaming) my CPU peaked at 85C. So my findings were that CM ROM has overclocked the CPUs excessively. They are set to 1900MHz, which has become obvious to me brings them right up to their temperature safety threshold, 95C. It seems Samsung clocked them at 1300MHz and allowed for occasional spikes above this point, keeping them at a maxium & slightly more reasonable 85C a full 10C cooler than their maximum safe operating temp.
I never expected I'd stumble on not only a source, but also that I've been utilizing the solution for months. I should add that governing the CPU lower has had absolutely no effect on performance. I regularly shut down 1 or 2 CPU cores as it is. I found that the tablet will run perfectly under normal use with only 2 cores. This reduces temperature and increases battery life. Sluthing can be so much fun sometimes, it was right in front of my face I just never put 2 & 2 together lol :good:
Thanks for your detailed comparison, that's very helpful indeed! In light of that, I think my mod has indeed given some improvement, as I don't reach over 90°C on CM13 until after 5-10 min, albeit with some throttling to 1700MHz after about 10min.
I've always had the impression that the current CM13 builds are a bit more CPU hungry and run warmer (possibly that triggered my thinking about a cooling mod in the first place), so it's very interesting to see that backed up experimentally! Interestingly, I've had mixed experiences with CM13, almost like two "modes" of running - sometimes, it runs pretty warm, roughly like you describe, but at other times it runs fairly normally around 30-40°C without problems. Haven't really figured out what the problem is and am having occasional instabilities/reboots as well, so I might actually also return to CM12.1 for the moment too.
While the higher CPU clocks (although 1.9GHz is the specified clock speed, but I get what you mean) may explain the heat and slightly better results in Geekbench I've been having with CM13, it's a bit odd that I still get the good result when the ROM is in the cool "mode" (it goes up to high 60s, mid 70s during Geekbench if memory serves well).
How do you set your governors? And have you been able to get the cores to switch on and off automatically as they do on some other devices? Or is this not implemented in the kernel or something?
franzli said:
Thanks for your detailed comparison, that's very helpful indeed! In light of that, I think my mod has indeed given some improvement, as I don't reach over 90°C on CM13 until after 5-10 min, albeit with some throttling to 1700MHz after about 10min.
I've always had the impression that the current CM13 builds are a bit more CPU hungry and run warmer (possibly that triggered my thinking about a cooling mod in the first place), so it's very interesting to see that backed up experimentally! Interestingly, I've had mixed experiences with CM13, almost like two "modes" of running - sometimes, it runs pretty warm, roughly like you describe, but at other times it runs fairly normally around 30-40°C without problems. Haven't really figured out what the problem is and am having occasional instabilities/reboots as well, so I might actually also return to CM12.1 for the moment too.
While the higher CPU clocks (although 1.9GHz is the specified clock speed, but I get what you mean) may explain the heat and slightly better results in Geekbench I've been having with CM13, it's a bit odd that I still get the good result when the ROM is in the cool "mode" (it goes up to high 60s, mid 70s during Geekbench if memory serves well).
How do you set your governors? And have you been able to get the cores to switch on and off automatically as they do on some other devices? Or is this not implemented in the kernel or something?
Click to expand...
Click to collapse
Your welcome. I too noticed that on CM13 at times it seems to run alot cooler than at other times. Although the only time I ever see go as low as 30C is when its been asleep for awhile and then I turn the screen on (CM12 & 13). As soon as it wakes up it'll go to mid-high 40C to mid 50C (on CM12) or it'll go straight to high 50C to low 60C (CM13). CM13 definitely ramped up alot quicker when testing, almost like its either min or max CPU power. I like temaseks CM13 build, but for me there wasnt much improvement over the CM12 build. Plus there is a few minor bugs as well as the slight negative effect on battery life I noticed. Plus I was noticing that there was a bit of a touchy spot in the top right corner of my screen that when swiped from the outside in, it sometimes crashed my tablet. I wasn't sure if it was a fault in my tablets hardware or something software related and I'm still not 100% positive which it may be, but since I began taking notice of when it was happening, its only ever happened on CM13. Thats also part of the reason I think I'm going to hold off on using the CM13 build for awhile. CM12 build is overall just more to my liking I guess... more to my tablets liking as well.
After posting yesterday I looked up some specs on Samsungs website and you are 100% correct about it being 1.9GHz. This is the spec copy/pasted off their website... Exynos® 5 Octa (1.9GHz Quadcore + 1.3 GHz Quadcore). The second part stands out because 1.3GHz is definitely where the stock rom was trying to maintain its CPU frequency when under heavy load. Not once did it exceed 1.6GHz. Whereas both CM builds ramped up to the full 1.9GHz very quickly. So the difference is going to be HOW the processor steps up in frequency as opposed to what the frequency actually is. Thats where my knowledge on that kinda stuff ends. I'm a "let's figure out what failed and why" or "lets figure out how it works" type of person. Thats why I work on cars for a living. I leave the development and detailed technical mumbo jumbo to the devs and engineers. Troubleshooting methods are much the same for just about everything though, hince how I came to my conclusion yesterday. Just for grins I may load up PAC ROMs CM12 build, see how it does. too...
As for how I set my governor, it depends on what I doing at the time. I never fine tune anything, like I said, that's outside my realm of knowledge. What I do set is the governor to either interactive or ondemand. Interactive more for casual use and ondemand more for gaming. I also manually shut down CPU cores depending on my demand from my CPU. Right now, for instance, I'm running stricly on cores 0 & 2 with cores 1 & 3 turned off. My CPU max clocking frequency is set to 1.3GHz but its consistantly hovering at 650MHz, or .65GHz. Thats all I ever mess with and I do so mainly for battery life. It makes a noticeable difference (both charging and discharging) if I adjust those 3 things according to my use. And no, my cores don't ever switch on or off automatically. I do vaguely recall seeing them do that on a different ROM, but I don't remember what ROM that was... it was at least a year ago that I saw that. I'm sure that is something that is kernel related, but I'm just guessing on that one.
What exactly did you mod? Any pictures?
thebadwrench said:
Your welcome. I too noticed that on CM13 at times it seems to run alot cooler than at other times. Although the only time I ever see go as low as 30C is when its been asleep for awhile and then I turn the screen on (CM12 & 13). As soon as it wakes up it'll go to mid-high 40C to mid 50C (on CM12) or it'll go straight to high 50C to low 60C (CM13). CM13 definitely ramped up alot quicker when testing, almost like its either min or max CPU power. I like temaseks CM13 build, but for me there wasnt much improvement over the CM12 build. Plus there is a few minor bugs as well as the slight negative effect on battery life I noticed. Plus I was noticing that there was a bit of a touchy spot in the top right corner of my screen that when swiped from the outside in, it sometimes crashed my tablet. I wasn't sure if it was a fault in my tablets hardware or something software related and I'm still not 100% positive which it may be, but since I began taking notice of when it was happening, its only ever happened on CM13. Thats also part of the reason I think I'm going to hold off on using the CM13 build for awhile. CM12 build is overall just more to my liking I guess... more to my tablets liking as well.
After posting yesterday I looked up some specs on Samsungs website and you are 100% correct about it being 1.9GHz. This is the spec copy/pasted off their website... Exynos® 5 Octa (1.9GHz Quadcore + 1.3 GHz Quadcore). The second part stands out because 1.3GHz is definitely where the stock rom was trying to maintain its CPU frequency when under heavy load. Not once did it exceed 1.6GHz. Whereas both CM builds ramped up to the full 1.9GHz very quickly. So the difference is going to be HOW the processor steps up in frequency as opposed to what the frequency actually is. Thats where my knowledge on that kinda stuff ends. I'm a "let's figure out what failed and why" or "lets figure out how it works" type of person. Thats why I work on cars for a living. I leave the development and detailed technical mumbo jumbo to the devs and engineers. Troubleshooting methods are much the same for just about everything though, hince how I came to my conclusion yesterday. Just for grins I may load up PAC ROMs CM12 build, see how it does. too...
As for how I set my governor, it depends on what I doing at the time. I never fine tune anything, like I said, that's outside my realm of knowledge. What I do set is the governor to either interactive or ondemand. Interactive more for casual use and ondemand more for gaming. I also manually shut down CPU cores depending on my demand from my CPU. Right now, for instance, I'm running stricly on cores 0 & 2 with cores 1 & 3 turned off. My CPU max clocking frequency is set to 1.3GHz but its consistantly hovering at 650MHz, or .65GHz. Thats all I ever mess with and I do so mainly for battery life. It makes a noticeable difference (both charging and discharging) if I adjust those 3 things according to my use. And no, my cores don't ever switch on or off automatically. I do vaguely recall seeing them do that on a different ROM, but I don't remember what ROM that was... it was at least a year ago that I saw that. I'm sure that is something that is kernel related, but I'm just guessing on that one.
What exactly did you mod? Any pictures?
Click to expand...
Click to collapse
Hi thebadwrench,
Which app did you use to do all this modifications on cm13 stock kernel? Especially deactivating cores is very interesting. Can you see all eight cores? I'm using 3C toolbox and it shows it only as quad core and on voltage page I have two cpu cluster.(one clocked till 650mhz and the other till 1900mhz)
Under CM13 the cpu behavior is totally different as on stock Samsung roms because the small cores are more or less unused and clocked at max. only at 650mhz, Lol!
I watch also much more kernel warnings in ksmg and high temperatures for a while now on CM13.
Also battery runtimes are only 3,5-5h unlike 7-8h under cm12.1!
Sometimes the cpu is also locked at max. speed(1,9ghz), mostly after looking youtube videos or other heavy load situations. The only way to get back "normal" behavior is to reboot the device.
I see also only two used cpu states all the time it jumps between 250 and 1900mhz, the most steps in between are unused.
We can only hope a real kernel developer can have a look on this or we can cherry pick some usefull tweaks from another device with the same cpu chipset.
ollimi1 said:
Hi thebadwrench,
Which app did you use to do all this modifications on cm13 stock kernel? Especially deactivating cores is very interesting. Can you see all eight cores? I'm using 3C toolbox and it shows it only as quad core and on voltage page I have two cpu cluster.(one clocked till 650mhz and the other till 1900mhz)
Under CM13 the cpu behavior is totally different as on stock Samsung roms because the small cores are more or less unused and clocked at max. only at 650mhz, Lol!
I watch also much more kernel warnings in ksmg and high temperatures for a while now on CM13.
Also battery runtimes are only 3,5-5h unlike 7-8h under cm12.1!
Sometimes the cpu is also locked at max. speed(1,9ghz), mostly after looking youtube videos or other heavy load situations. The only way to get back "normal" behavior is to reboot the device.
I see also only two used cpu states all the time it jumps between 250 and 1900mhz, the most steps in between are unused.
We can only hope a real kernel developer can have a look on this or we can cherry pick some usefull tweaks from another device with the same cpu chipset.
Click to expand...
Click to collapse
I use kernel adiutor https://play.google.com/store/apps/details?id=com.grarak.kerneladiutor It also shows 4 cores but shutting them down is just a single click. In the attached screenshot you can see that I've manually unchecked cores 1 & 2 and on the CPU display (turned on via developer options) you can see that those cores are indeed shut down and not operating. I like the app's widget, allows you to set up as many different profiles as you want and then change between the different profiles on the widget.
thebadwrench said:
I use kernel adiutor https://play.google.com/store/apps/details?id=com.grarak.kerneladiutor It also shows 4 cores but shutting them down is just a single click. In the attached screenshot you can see that I've manually unchecked cores 1 & 2 and on the CPU display (turned on via developer options) you can see that those cores are indeed shut down and not operating. I like the app's widget, allows you to set up as many different profiles as you want and then change between the different profiles on the widget.
View attachment 3732472
Click to expand...
Click to collapse
Yeah, good news!
I am positive surprised that kernel Adiutor is working, seems we have build-in UCI, which is needed, nice! Using KA on my OP2 since a long time but there is no custom kernel for p600 cm13 roms so I have not tried!
Will try it now!:good:
Thanks!!
thebadwrench said:
What exactly did you mod? Any pictures?
Click to expand...
Click to collapse
I replaced the silicone heat pad on the CPU with a copper shim and thermal compound, added some small silicone pads around other components (all under the heat shields) and added a .5mm silicone heat pad on top of the main heat shield to enhance contact with the back plate. I do have some pictures, but I want to provide a proper write-up and currently don't have much time as I'm moving. Will hopefully find a chance to give a more detailed write-up in May - sorry for the delay, but full report is forthcoming!
As for the CM13 issues, @joshndroid apparently implemented some changes to it in the last build, so I might check that out, although I agree that CM12.1 is probably still the safer bet for a stable daily driver.
franzli said:
Thanks for your detailed comparison, that's very helpful indeed! In light of that, I think my mod has indeed given some improvement, as I don't reach over 90°C on CM13 until after 5-10 min, albeit with some throttling to 1700MHz after about 10min.
I've always had the impression that the current CM13 builds are a bit more CPU hungry and run warmer (possibly that triggered my thinking about a cooling mod in the first place), so it's very interesting to see that backed up experimentally! Interestingly, I've had mixed experiences with CM13, almost like two "modes" of running - sometimes, it runs pretty warm, roughly like you describe, but at other times it runs fairly normally around 30-40°C without problems. Haven't really figured out what the problem is and am having occasional instabilities/reboots as well, so I might actually also return to CM12.1 for the moment too.
While the higher CPU clocks (although 1.9GHz is the specified clock speed, but I get what you mean) may explain the heat and slightly better results in Geekbench I've been having with CM13, it's a bit odd that I still get the good result when the ROM is in the cool "mode" (it goes up to high 60s, mid 70s during Geekbench if memory serves well).
How do you set your governors? And have you been able to get the cores to switch on and off automatically as they do on some other devices? Or is this not implemented in the kernel or something?
Click to expand...
Click to collapse
Hi Franzli,
The kernel seems odd to me!
The small A7 cluster is virtually unused and clocked only to 650MHz @ 1200ma !! Normal is 1.3GHz @ 1200ma for the small A7 cluster on 5420! Also a lot of warnings and errors in ksmg!
No idea whether the A7 ever used or permanently in idle mode, Lol!
Also all 4 big a15 cores are always online, what means no hotplug driver available!
I don't know if we will ever see a good kernel for CM13 because of the missing sources.
Although the kernel is running and mostly stable it is far from "good"!
Power consumption is almost doubled, problems with overheating and sometimes cpu is locked at max. speed and the only way to solve it is a reboot.
I don't remember the cm12.1 kernel but he was definately better in terms of battery runtimes and reliability.
BTW, I'll also mod the device cooling using bigger copper sheets instead of the perforated aluminum sheets, thermal-pads and thermal-grease when I start changing my battery and usb jack, what is definately neccessary in my case!
Maybe I will buy one of the small heatpipes used in S7 or so when I find them somewhere.
It is not difficult to adjust it if needed, so that it can replace the heatspreader.
Mabye it is needed to isolate the heatpipe from the mainboard but nothing what a piece of kapton tape not can do.
franzli said:
Hi all!
[...] But after seeing this video on the Teclast X98 Pro and some other info on modding in tablets, I was still wondering if there'd be a way to improve the cooling on the Note 10.1 2014 to get lower average temperatures [...]
So I guess my main question is if anyone has undertaken anything of this sort for this or comparable tablets? [...]
Click to expand...
Click to collapse
Hallo there
Well I just did the job. I have also made a short manual and would like to share it with you. But first some things about me and my tablet.
I bought a used galaxy note 10.1 2014 edition SM-P600 couple months ago. I was really disappointed about the device performance. Switching from stock android 5.1 to [ROM][7.1.2]Resurrection Remix N for SM-P600 (n1awifi) [5.8.5][UNOFFICIAL][NIGHTLY] did some improvements in performance. But since I am a very heavy web surfer I was still not satisfied with the performance. I have also tried [P600][Touchwiz] Marshmallow Rom 20170622 and went back to RR because I can play around with the CPU governors and all that deathy audiutor stuff. Between very nice work Exynos Team and all the other developers...
Soon I realized that the SM-P600 becomes fairly hot in the backside. I took a look at the ifixit pictures. There was no other way finding good resolution pictures of the inside.
I ended up installing cool tool app. Well is there any other good app for monitoring temps, clock and load in overly?
Well so I added frequency, load, battery temp and cpu temp. You need to add cpu temp manually. I guess it is Label ->
custom label -> enable- Then you have to go fine tuning -> custom label -> path:/sys/class/thermal/thermal_zone0/temp. leace everything as it is. regex is (\d+)\d{3} and add postfix °C and prefix cpu:
.
So I went along and analysed heat and temps in the galaxy 10.1 2014 edition. Especially frequency-temp-ratio. And I can tell you this buddy is everything else than cool. Temps jump up so fast I can't tell you. Even some fast scrolling on ebay, facebook desktop web page in browser treated the Temperature to the hight 80s and soon the high 90s. I have also seen the things franzli mentioned before. Even light work put so much heat to the processor. Watching the frequency and temperature bounce was a pain. I could feel the pain that little Exynos 5420 must suffer of all the time.Throttling is the only ways this little buddy can survive To make it short I decided to do the cooling mod...
So lets see what I found on my journey ... I can tell you that's a big surprise
I opened the case very easily. You can find tons of videos on youtube or use ifixit.
Well I have to mention I am an electronics hardware engineer. So doing this stuff is nothing unique for me. And I have years of professional PCB manufacturing, repair experience.
Opening the case, adding some tape and this is what you get...
As you can see there is a little thermal pad applied to the aluminium shielding. And boooom there you are . Do you see all thet flux solder remains? How come samsung? Seriously?
This is the shielding close up with that thermal pad.
As you can see the FBGA package is covered with flux from soldering. So it is naturally, that the cooling in the galaxy is a pain. There can't bee any good heat flow.
So let's check that thermal pad.
woops that little buddy is kinda to small. I am sad to see this.
Well I cleaned the surface as good as I can with ethanol. After this I applied a new Thermal pad.
After that it looked like this.
Then I closed the shielding case and cleaned it.
So next comes the actual cooling mod. I added a big thermal pad.
I had to cut that little hook in the back plate. So that the 100mmx100mm copper layer will fit in shape.
And this is it done.
So what about the results :laugh:
The back plate fits perfectly. If you know there is a thin layer of copper you can feel it. But it is so less. I had no problem closing the case. Ahh yeah I had to tage it with double sided tape, so it is pressed down to the thermal. The back plate will do the rest pressure.
And really don't worry about the wifi interference. There is no worry. Because the copper layer is located on top of the bettery pack and shielding case. Why should there be any interference? I have tried. Reaching same wifi performance as always. No worries:good:
So what about heating. Well my galaxy note stays pretty cool.
I need to mention this is all mesured with the [ROM][7.1.2]Resurrection Remix N for SM-P600 (n1awifi) [5.8.5][UNOFFICIAL][NIGHTLY] I mentioned before.
I used interactive governor.
I reach in Antutu v6.2.7 about 57000 to 58000
In futuremark work 2.0 I get 4000
Here some pics
I am sorry for that high resolution pics. But I wanted best of (bad) quality. I used my redmi note 4 for taking pictures. If you can't read all in the pics, just open in new window.
There isn't any more throttling at all. It is hard to push to 85°C or above now. Just with synthetic GPU and CPU load on all four cores at once. And it takes a couple of minutes. But in real world you will never get it. With only load on one core my maximum is 69 to 72°C. The tablet fells pretty nice now. The warming in the back plate is reduced to a very large surface. So sometimes it fells as if your hands warm up the case.
Can you suggest me any ROm with a good overclocking potential? I have already tried this ROM. I really don't know why, but it keeps crashing all the time at 2GHz or 2.1 GHz. Even with no load at all. I guess the used kernel is bad.
Do you have any ROM suggestion for me.
If you have any quastions and things you want me to test write me.
Just wanted to share my experience with you. I didn't expect a dirty PCB, BGA and thermal pad like this. So what do you think about this.

Question Is there any way to increase the temperature control threshold?

I have gained root privileges. As you know, pixel6Pro has a strict temperature limit. This means that once the temperature of the mobile phone rises to about 40°C, the processor will start to reduce the operating frequency. When it reaches 43°C, all cores will not be allowed to work at a frequency above 1G... This will cause the phone to freeze very much. So will there be any mods to turn it off? I have an extra phone cooler./translate form Google
So you'd rather it have unlimited temperature to cause components to melt? There's a good reason why there is a temperature limit. I suggest that you don't mess around with it, or you will end up with a heap of garbage.
96carboard said:
So you'd rather it have unlimited temperature to cause components to melt? There's a good reason why there is a temperature limit. I suggest that you don't mess around with it, or you will end up with a heap of garbage.
Click to expand...
Click to collapse
I mean to increase the upper limit instead of closing it ... I also have a Redmi K40, equipped with Snapdragon 870, and the phone temperature exceeds 48 ° C to start limiting the processor frequency ... In contrast, TensorG1's frequency limit from less than 40 ° C is too early..For example, at room temperature of 23 ° C, my Pixel6Pro played at a current of about 1A (power consumption of about 4W). About 15 minutes, the back cover temperature of the mobile phone would be close to 40 ° C, and then a disgusting frequency limit appeared. 40 ° C is very safe for the phone, isn't it? And the lower area of the Pixel6Pro heating speed is much faster than the camera area and processor area, which is not common sense, and I also want to know why.If the frequency limit starts at about 46 ° C, it will be a good choice.
I think people should study electronics first before they tinker. This is proof. MORE HEAT?
Gytole said:
I think people should study electronics first before they tinker. This is proof. MORE HEAT?
Click to expand...
Click to collapse
Thank you for your reply, but I can't understand what you mean by translating.
He means that different devices have different specification, and you will likely damage your device.
Arealhooman said:
He means that different devices have different specification, and you will likely damage your device.
Click to expand...
Click to collapse
But this is based on root, which has assumed that I bear all the consequences, right? Having said that, the Pixel6Pro is the phone with the lowest temperature limit I have ever used.Even the same garbage Snapdragon 888 chip has a frequency limit at about 43 ° C.I just use it to run small games, but it can't last for too long, which makes me wonder if this can be called a flagship phone. Leaving aside the peak performance, the Snapdragon 778G is much better than Tensor in many scenes.And Google made a lot of mistakes. In fact, the X1 core is much more efficient than the A76 core, but I don't understand why the more used is the A76 core? ? ? I like to test the power consumption data of the processor. After about half a month I conclude that [email protected] and [email protected] have almost the same performance, but the latter one needs to pay an additional power of about 0.25W+.Too crazy,right?
Juuuuune said:
But this is based on root, which has assumed that I bear all the consequences, right? Having said that, the Pixel6Pro is the phone with the lowest temperature limit I have ever used.Even the same garbage Snapdragon 888 chip has a frequency limit at about 43 ° C.I just use it to run small games, but it can't last for too long, which makes me wonder if this can be called a flagship phone. Leaving aside the peak performance, the Snapdragon 778G is much better than Tensor in many scenes.And Google made a lot of mistakes. In fact, the X1 core is much more efficient than the A76 core, but I don't understand why the more used is the A76 core? ? ? I like to test the power consumption data of the processor. After about half a month I conclude that [email protected] and [email protected] have almost the same performance, but the latter one needs to pay an additional power of about 0.25W+.Too crazy,right?
Click to expand...
Click to collapse
Its a different SoC and different phone altogether, and the temperature reading could be from a different point, and it takes time for the heat to be conducted from the point of highest temperature to the sensor, which means that when you have a READING of 40C, the actual highest temperature point could be 75C.
Arealhooman said:
He means that different devices have different specification, and you will likely damage your device.
Click to expand...
Click to collapse
But you won't. Removing the OEM throttling mechanism doesn't completely remove throttling. The SOC WILL throttle regardless of when it hits the set TjMax.
Also, the throttling they set is based on SKIN/Shell temperatures, usually on Pixel 6/7 starting around 37c SKIN, that's on the battery around 37c (all approximate). I don't own the Pixel 6, but the 7, and the SKIN temperature is set to start at 37c very mild throttling, and the more the temperature rises, the throttling level increases.
Ultimately, the "only" hardware that will suffer in the LONG RUN is the battery since batteries don't like high temperatures and degrade faster when exposed to XY temps.
Juuuuune said:
But this is based on root, which has assumed that I bear all the consequences, right? Having said that, the Pixel6Pro is the phone with the lowest temperature limit I have ever used.Even the same garbage Snapdragon 888 chip has a frequency limit at about 43 ° C.I just use it to run small games, but it can't last for too long, which makes me wonder if this can be called a flagship phone. Leaving aside the peak performance, the Snapdragon 778G is much better than Tensor in many scenes.And Google made a lot of mistakes. In fact, the X1 core is much more efficient than the A76 core, but I don't understand why the more used is the A76 core? ? ? I like to test the power consumption data of the processor. After about half a month I conclude that [email protected] and [email protected] have almost the same performance, but the latter one needs to pay an additional power of about 0.25W+.Too crazy,right?
Click to expand...
Click to collapse
The temperature limits DEPEND on the OEM. It's NOT SOC SPECIFIC.
CPU and GPU are MOSTLY set to 85c/95c on Qualcomm Snapdragon SOCs. Pixel 7 series has the CPU set to 100C TjMax (I think the GPU is set to 95c, didn't check...)
The throttling you're talking about is based on the SKIN/Shell and EACH OEM has its own way of tunning this throttling mechanism.
JohnTheFarm3r said:
The temperature limits DEPEND on the OEM. It's NOT SOC SPECIFIC.
CPU and GPU are MOSTLY set to 85c/95c on Qualcomm Snapdragon SOCs. Pixel 7 series has the CPU set to 100C TjMax (I think the GPU is set to 95c, didn't check...)
The throttling you're talking about is based on the SKIN/Shell and EACH OEM has its own way of tunning this throttling mechanism.
Click to expand...
Click to collapse
The temperature limit of a specific SoC is determined by the characteristics of *that SoC*, not by whoever glues parts together.
96carboard said:
The temperature limit of a specific SoC is determined by the characteristics of *that SoC*, not by whoever glues parts together.
Click to expand...
Click to collapse
I'm suggesting you go and check (inform/educate yourself) a bit on this topic and how exactly this works. A SOC has an operating temperature range (from-to), THAT IS VERY TRUE (and I'm not talking about the operating temperature range specification here) but OEM decides what TJMax they want to set on the CPU or GPU (or any other component inside the phone)
So, if the OEM wants, they can set the TJMax for the CPU at 110c or more. Obviously, they don't do this for various reasons and most importantly to decrease the degradation of the silicon as much as possible (lower temps, longer life). And if you're experienced enough and know how to configure the throttling you can raise the Tjmax yourself. Google raised the TjMax on Tensor G2 to 100c. G1 was set to 90c, but they could have set it to 100C too if they wanted. And this is done on the OS side. (OEM side)
For your information, on Tensor (both G1 and G2), you can raise the TJMax of the CPU or GPU (or any other component) just by editing the thermal zones inside sys/devices/virtual/thermal > Thermal Zones (needs root).
And as someone who already made various thermal mods (magisk modules for various devices), I'm VERY well aware of how is thermal throttling handled and what can be done.
JohnTheFarm3r said:
I'm suggesting you go and check (inform/educate yourself) a bit on this topic and how exactly this works. A SOC has an operating temperature range (from-to), THAT IS VERY TRUE (and I'm not talking about the operating temperature range specification here) but OEM decides what TJMax they want to set on the CPU or GPU (or any other component inside the phone)
So, if the OEM wants, they can set the TJMax for the CPU at 110c or more. Obviously, they don't do this for various reasons and most importantly to decrease the degradation of the silicon as much as possible (lower temps, longer life). And if you're experienced enough and know how to configure the throttling you can raise the Tjmax yourself. Google raised the TjMax on Tensor G2 to 100c. G1 was set to 90c, but they could have set it to 100C too if they wanted. And this is done on the OS side. (OEM side)
For your information, on Tensor (both G1 and G2), you can raise the TJMax of the CPU or GPU (or any other component) just by editing the thermal zones inside sys/devices/virtual/thermal > Thermal Zones (needs root).
And as someone who already made various thermal mods (magisk modules for various devices), I'm VERY well aware of how is thermal throttling handled and what can be done.
Click to expand...
Click to collapse
Thank you for your reply. In the file directory you mentioned, I found many files starting with "thermal_zone" followed by numbers. But I'm not good at this field, can you tell me more? I know you have a magisk module for pixel7Pro, I want to know if you can modify some parameters to make it work on pixel6Pro? （Or are they inherently universal?） I have a pixel6Pro which rooted , maybe it can be used for your test.

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