Develop Bugs

Pershoots kernel or CM kernel?

I'm on the latest CM7 build and would like to know the pros and cons of using each kernel. Hopefully someone can enlighten me.
I'm on Pershoot's right now, btw.

personally i like the pershoot kernels, they give u more frequencies to choose from... now this isnt really a big deal when u picking the overclock frequency (844Mhz vs 864Mhz vs 883Mhz isnt a big difference really), but given that the kernel can vary the frequencies in real-time means that the kernel has more options to chose from, also given a good algorithm that picks the frequencies it should result in better performance and less battery use (theoretically since the power required for 806MHz is less than 883Mhz).
Also pershoot kernels are UV, which should mean that the CPU is using less power to run at any given frequency (compared to running at that exact frequency with a non UV kernel).
Having said so, CM kernel gives u more options regarding the governors, under the original CM kernel i always picked the Conservative governor which gave me amazing battery life... this option is not available under the pershoot kernel and i believe pershoot recommends using the OnDemand option (not a 100% on this one though).
so in my opinion, and if am correct it's mostly a preference thing. I use the pershoot kernels.
let me know if am missing anything

awsrasool said:
personally i like the pershoot kernels, they give u more frequencies to choose from... now this isnt really a big deal when u picking the overclock frequency (844Mhz vs 864Mhz vs 883Mhz isnt a big difference really), but given that the kernel can vary the frequencies in real-time means that the kernel has more options to chose from, also given a good algorithm that picks the frequencies it should result in better performance and less battery use (theoretically since the power required for 806MHz is less than 883Mhz).
Also pershoot kernels are UV, which should mean that the CPU is using less power to run at any given frequency (compared to running at that exact frequency with a non UV kernel).
Having said so, CM kernel gives u more options regarding the governors, under the original CM kernel i always picked the Conservative governor which gave me amazing battery life... this option is not available under the pershoot kernel and i believe pershoot recommends using the OnDemand option (not a 100% on this one though).
so in my opinion, and if am correct it's mostly a preference thing. I use the pershoot kernels.
let me know if am missing anything
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Click to collapse
Thank you so much! Just the answer I was looking for! Very informative and straight-forward, thanks.
Looks like I'll be sticking to Pershoot's.

awsrasool said:
Having said so, CM kernel gives u more options regarding the governors, under the original CM kernel i always picked the Conservative governor which gave me amazing battery life... this option is not available under the pershoot kernel and i believe pershoot recommends using the OnDemand option (not a 100% on this one though).
Click to expand...
Click to collapse
You're correct. Pershoot uses the ondemand governor because he says it's more stable at the higher cpu clock cycles. Few issues with FC's, lockups, and reboots. Though I do love the interactive governor (still want the smartass gov) he is correct from what I've personally experienced. That may be due to small variances in the kernels though despite coming from the same source but who knows.
Pershoot also has a .zip for every kernel that's full of some /lib files to add extra functions to your device, most users probably won't find a use for them though.

KCRic said:
Pershoot also has a .zip for every kernel that's full of some /lib files to add extra functions to your device, most users probably won't find a use for them though.
Click to expand...
Click to collapse
Can you please explain these extra functions and how to apply them please?
Wouldn't mind having some new functions
Sent from my HTC Vision using XDA App

I've found I get better battery life with Pershoot's kernel compared to the stock CM kernel using the same clocks speeds and governor (245 Mhz-1017 Mhz, Ondemand). No statistics to throw up though.

Undervolting

I wanted to know some more about undervolting and was hoping someone could help and explain a bit. Basically, what I'm seeing is when I undervolt my device on the max side of things, eventually the device freezes and needs a battery pull or reboots. When I don't touch the max voltage values and only drop the min values the phone seems more stable and doesn't reboot. Can someone explain if my thinking of only undervolting the min values is correct and why this may be happening. Also, what would be the proper way to undervolt the phone? I have been using system tuner to do so on deck's 1.3 ROM using the Lee +sbc kernel. Thanks for taking the time to read this and for all the helpful responses.
Sent from my Decked Evo running Lee+sbc... It's easier this way.

I have this same question! I was trying to figure this out becuase the freedom kernels have something to do with under and over voltage to allow better OC? not sure on why the you would need and over voltage to over clock?...

What is your ROM/Kernel setup?
Remember that undervolting and underclocking are two different things. Over/underclocking, via apps like setcpu, raise/lower the frequency at which your processor operates. Over/undervolting raises/lowers the power voltage available to your processor at any given frequency. This can potentially cause problems if you have a kernel set to undervolt your processor while running an app like setcpu to overclock it. This may be why you are seeing issues with your phone.

pmacevad said:
[snip]
I have been using system tuner to do so on deck's 1.3 ROM using the Lee +sbc kernel.
[snip]
Sent from my Decked Evo running Lee+sbc... It's easier this way.
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Concordium said:
What is your ROM/Kernel setup?
Click to expand...
Click to collapse
OP clearly states he's running Deck's 1.3 and Tiamat 3.3.7 (aka LEE kernel)
OP should also state Deck's ROM version but I'm assuming 1.3d as it's most popular next to 1.3 Stable.
I'm running the same setup - Deck's 1.3d with LEE SBC. I'd like someone to explain (as the OP also asked) the difference between the MIN and MAX sides of the undervolting equation please.
(I do understand underclocking AND that it is a separate and different animal and for the record, my EVO is UC'd to 128/499MHz and using Smartass governor)
I'm just not sure what I'm looking at in the ST interface (what's the first number and what's the number in [] brackets?) and also not sure just why there is both a min and max voltage for each frequency and how it affects performance.
Thanks much for any inputs.
J.

I use vipermod and terminal emulator for aosp roms its much more stable than using system tuner and you can drop all voltages with a single command it all depends on your particular hardware but typically around -100 the phone will lag or freeze i usually stick to -50 at stock voltages and -25 on overclock i never overclock over 1075mhz as anything higher and my phone tries to cook my fingers however now im oc to 1.6ghz on my et4g with a 200mhz min and it stays nice and cool like it was clocked at 1.2ghz stock the exynos is capable of clock speeds up to 2 ghz but the phone doesnt handle those speeds well similar to the evo not liking anything over 1.19 at 1.2 on the evo theres a good chance of frying the logic board or bursting the battery from heat if you overclock dont undervolt too much as it makes the processor get really really hot due to it having to work harder from lack of energy to power it
We are legion, for we are many
Sent from my Anonymous DeathStar in the depths of GalaXy S2

To answer the min/max at each freq min is the lowest voltage that freq will run while idle max is the highest voltage the freq will run while in use the voltages are depenedant on the load running at the particular freq ie how many process' are running the more process' the higher the voltage required to power the processor
We are legion, for we are many
Sent from my Anonymous DeathStar in the depths of GalaXy S2

Is there an app the will show actual voltage the CPU is using in real time?
Sent from my Synergized Aggressive Lionfish Evo using the XDA app

bmw pro will u can set the mv on the widget or set recording in the app and it will log the info
We are legion, for we are many
Sent from my Anonymous DeathStar in the depths of GalaXy S2

I had a similar issue with undervolting and underclocking. I was setting my CPU min/max to 128-499 MHz and undervolting to -75 or -100 using Lee with Smartass v1. But I was getting too many random reboots and freezes on each ASOP rom I tried (e.g. Deck 1.3d, CM7).
I've been playing around with these settings. I changed my CPU to 128-576, no undervolting, and SZ 2.2.1 with SavagedZen governor. I haven't had any random reboots and my batter life is about the same...plus my phone is MUCH snappier. I'm still getting a little screen on lag but not nearly as much as I was at 128-499 and undervolted.
As a note, I normally run Deck 1.3d as my daily driver but for the last couple days I've been running KWIQ. It's definitely giving 1.3d a run for its money as becoming my daily driver.
Anywho, are there any rules of thumb with undervolting and underclocking? Like is 128 MHz is too low with -100 undervolting? Or are these things pretty much phone dependent? I know each phone seems to respond different to these things.

-EViL-KoNCEPTz- said:
To answer the min/max at each freq min is the lowest voltage that freq will run while idle max is the highest voltage the freq will run while in use the voltages are depenedant on the load running at the particular freq ie how many process' are running the more process' the higher the voltage required to power the processor
Click to expand...
Click to collapse
Thank you. That made good sense to me. Question then: is it suggested/typical to drop min and max by equal amounts or is it typical to drop min more (so there's juice for the proc under load but maybe being more aggressive with the sleeping/idle side of things or can the proc run at a given frequency at different voltages)?
jackfrost909 said:
I'm just not sure what I'm looking at in the ST interface (what's the first number and what's the number in [] brackets?)
Click to expand...
Click to collapse
Are you familiar enough with ST to shed some light on this? Please if so. Thank you.
detcup4evr said:
Is there an app the will show actual voltage the CPU is using in real time?
Click to expand...
Click to collapse
-EViL-KoNCEPTz- said:
bmw pro will u can set the mv on the widget or set recording in the app and it will log the info
Click to expand...
Click to collapse
Though I have to recheck this I don't remember BMW showing the voltage being used at each frequency just the overall voltage draw. If you know otherwise or another tool that does, please share
Thanks for all the help.
J.
--
Tapa Tapa Tapa..
Let's see.. My phone flies, my battery doesn't suck.. and your point was.... ?
OG EVO - Deck'd and LEE'd because it's just better this way.

Lionfish kernel
Has anyone tried undervolting with lionfish kernel on SENSE Roms, is it stable?

einstein562 said:
Has anyone tried undervolting with lionfish kernel on SENSE Roms, is it stable?
Click to expand...
Click to collapse
I use aggressive and it works well but some phones don't like it, hopefully I can get vipermod to work, and that will allow you to adjust each frequency independently
Sent from my Synergized Aggressive Lionfish Evo using the XDA app

I actually just got rid of lionfish aggressive on MikG3.11
I had a lot of lagginess, but battery life was really good... Back to anthrax for me, lionfish was based at one point on freedom kernels I thought, maybe one of those would be better...?
What's the best thing to use to control undervolting on sense roms?
Sent from my PC36100 using Tapatalk 2

Is the battery life improvement substantial when undervolting?
I have governators set at 240-650max and am getting decent life on my ics savoca kernel.
What % improvements are obtained?

Well I don't have logcats and scientific evidence, but I saw about 12 hour days, with moderate use, everything syncing, lots of text a few calls, hotspot for an hour or so, some web browsing, but the random revolts and lagginess on that was horrible, freedom was better.... It's worth it to underclock
I have everything set to 384-1152.
Different governors for profiles, screen off @ conservative because I have a lot to sync
Sent from my PC36100 using Tapatalk 2

[Q] SetCPU - Extra Info?

Hi there, thinking about getting SetCPU - I have some questions before I do because I hear it can be dangerous?
- I've heard it can brick your phone?
- What if you set it too high?
- Do you personally have to monitor it?
- What are the benefits?
- Use alot of battery?
- Is it really worth using?
- Is it optimized for different phones - example the One X?
Thanks guys!

JDBurnie said:
Hi there, thinking about getting SetCPU - I have some questions before I do because I hear it can be dangerous?
- I've heard it can brick your phone?
- What if you set it too high?
- Do you personally have to monitor it?
- What are the benefits?
- Use alot of battery?
- Is it really worth using?
- Is it optimized for different phones - example the One X?
Thanks guys!
Click to expand...
Click to collapse
Hi, i have read that SetCPU cannot view all the cores i have read alot saying that System Tuner works fine you might want to try that.
I used to use SetCPU on my sensation and never hand any issues with it i did not monitor the app at all
Benefits allows overclocking if available in kernel
it can be overclocked and cause some issues such as overheating but if set correctly will be fine doesnt use much battery if any
and no i dont think you can brick your phone
if you set it too high i believe i had to reflash rom nothing major
BTW this is based on my own knowledge and usage
Hope this helps

Thanks man

JDBurnie said:
Thanks man
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Click to collapse
How much battery life can you save using setCPU?

lamenramen said:
How much battery life can you save using setCPU?
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Click to collapse
None in theory, if the CPU is slower it takes longer to go from
idle - process - idle
Faster speeds allow it to get it over and done with faster and get back to idle.
Of course it will at times stop the CPU going higher than it needs too which could save battery.
Under volting will save more batter then underclocking ever will.
Sent from my HTC One X using xda premium

SetCPU can not see Tegra 3 yet
Use System Tuner and its free

hamdir said:
SetCPU can not see Tegra 3 yet
Use System Tuner and its free
Click to expand...
Click to collapse
Thanks. I have system tuner, but what do I need to do in order to improve battery life?
I have set the governor to powersave. Is there anything else? How would I undervolt using this app?

lamenramen said:
Thanks. I have system tuner, but what do I need to do in order to improve battery life?
I have set the governor to powersave. Is there anything else? How would I undervolt using this app?
Click to expand...
Click to collapse
undervolting requires your phones kernel to support it, currently on these forums there is only one that does but i haven't tested it, sticking firm to the "stock kernel is best" and will do untill the kernels have more time to mature.
you could limit your max speed to 1 GHz, if you are rooted you can use Core control to turn off cores and run your phone as a dual core.

treebill said:
undervolting requires your phones kernel to support it, currently on these forums there is only one that does but i haven't tested it, sticking firm to the "stock kernel is best" and will do untill the kernels have more time to mature.
you could limit your max speed to 1 GHz, if you are rooted you can use Core control to turn off cores and run your phone as a dual core.
Click to expand...
Click to collapse
Not to be lazy, but would running the phone as dual core and limiting it to 1 ghz result in a perceptible battery savings? I'm trying to get a feel for how much I should expect custom ROMs to make my One X perform up to par. Thus far, I've installed two custom ROMs and felt like the improvements were all safely in the minor category.
I did install cyanogenmod 7 on a phone last year wow, that resulted in major benefits.

lamenramen said:
Not to be lazy, but would running the phone as dual core and limiting it to 1 ghz result in a perceptible battery savings? I'm trying to get a feel for how much I should expect custom ROMs to make my One X perform up to par. Thus far, I've installed two custom ROMs and felt like the improvements were all safely in the minor category.
I did install cyanogenmod 7 on a phone last year wow, that resulted in major benefits.
Click to expand...
Click to collapse
Running on 2 cores stops the phone from using and 2 cores uses less power then 4, playing games and using all cores is over kill 2 cores will run the game without lag use less power and make less heat.
You'll maybe get 10% from doing that but I haven't tested.
Really the only time any of this saves battery is during demanding programs, tegrea has a super low power companion core, for all your power saving needs.
Sent from my HTC One X using xda premium

I tried conservative governor while downloading sd files for Nova3 gave execllent results
I strongly advice not to undervolt tegra3
t3 is not like any other chip and UV or OC should not be attempted
OC because the chip is already at the max of its thermals
UV for the same reason n might end up with problems like flicker
changing governors and UC should be enough

[Q] Which Kernel to use Galaxy S3

I am running CM10 M2 on my Samsung Galaxy S3 I747
Now my question is which kernel do i use because i would like to OC my phone but it has to have some speed and keeps some battery life.
I don't want to have a lot of speed with hardly to no battery life, i need a little speed plus good battery life if possible.
So if anyone has any suggestions please post

Leandre20 said:
I am running CM10 M2 on my Samsung Galaxy S3 I747
Now my question is which kernel do i use because i would like to OC my phone but it has to have some speed and keeps some battery life.
I don't want to have a lot of speed with hardly to no battery life, i need a little speed plus good battery life if possible.
So if anyone has any suggestions please post
Click to expand...
Click to collapse
You can try all that work with CM10. It's a preference thing. I'm using ktoonsez. You can OC and UC.
Sent from my SAMSUNG-SGH-I747 using xda premium

Im not saying there aren't any others as i have only used ktoonez's kernel, http://forum.xda-developers.com/showthread.php?t=1756776 simply because there is, IMHO, no need to. He has versions for each of the available android versions for the i747...obviously you would want to use the AOSP JB based kernel under CM10. Packaged along with the kernel is ktweaker which is an app that gives you control over the clock speeds, under volting, governors, schedulers, plus a bunch of other options. If you overclock your processor you are going to drain the battery faster, you can compensate for this by under volting the frequencies however pushing the CPU too hard can shorten the life expectancy and under volting too far will cause severe system instability. Im not sure how much experience you have with OC/UV'ing but its basically trial and error until to find the right balance of speed and stability that is right for you.Just be sure to read and follow his instructions carefully and dont mess with anything in ktweaker you aren't 100% sure what it does, and as always make a backup in your recovery before messing with system files.....happy OC'ing.

dntesinfrno said:
Im not saying there aren't any others as i have only used ktoonez's kernel, http://forum.xda-developers.com/showthread.php?t=1756776 simply because there is, IMHO, no need to. He has versions for each of the available android versions for the i747...obviously you would want to use the AOSP JB based kernel under CM10. Packaged along with the kernel is ktweaker which is an app that gives you control over the clock speeds, under volting, governors, schedulers, plus a bunch of other options. If you overclock your processor you are going to drain the battery faster, you can compensate for this by under volting the frequencies however pushing the CPU too hard can shorten the life expectancy and under volting too far will cause severe system instability. Im not sure how much experience you have with OC/UV'ing but its basically trial and error until to find the right balance of speed and stability that is right for you.Just be sure to read and follow his instructions carefully and dont mess with anything in ktweaker you aren't 100% sure what it does, and as always make a backup in your recovery before messing with system files.....happy OC'ing.
Click to expand...
Click to collapse
I'm still learning since it's the first one I tried.
Sent from my SAMSUNG-SGH-I747 using xda premium

There is a thread dedicated to ktweaker settings on the i747 HERE that would be a good place to start and get an idea of what you are doing. There are also several topics that discuss the different governors and schedulers, what the differences are, advantages/disadvantages to each etc. You can also search google for a plethora of information regarding OC/UV'ing, although most of it will pertain to desktop processors and video cards. While the voltages and frequencies will be significantly lower the same principles apply with mobile device chips.

Some n00b questions regarding Overclocking/Kernals

Hi guys,
I've got a Galaxy S3 via Rogers, rooted, running the rom Triune II, I haven't messed around with custom Kernals (tbh haven't figured that out really), I recently installed SetCPU to overclock my S3 for running graphic intensive/slow loading games like Asphalt 7, etc.
So far for that purpose it's been amazing, the games literally open twice as fast. I've setup SetCPU for a variety of CPU changes, ie. higher speeds for graphic intensive games, lower speed for screen off while charging (ie. overnight) and it seems to be working great.
My questions are:
Can "overclocking" damange my device? Ie. I know that obviously overclocking shreds through battery life, but is playing a game at the top speed available on SetCPU (1512 Mhz) bad over a prolonged period?
Also, am I not reaping the full benefits of over/underclocking having a custom kernal installed?
Also...nother totally n00b one, if the S3 is capable of reaching the "overclocked" max speed, why doesn't it in the stock ROM? I just don't quite get that....is it because the battery life would be terrible and people would blame Samsung for it?

Never had a issue overclocking. And I've overclocked every phone I've owned beside the iPhone.
As far as how much better it will make your phone it depends. Depends on the rom too. I've noticed better benchmark results yet not always better real world results.
I use it more for the ability to underclock, and overclock when necessary.
Sent from my SGH-I747 using xda app-developers app

a little off but do you know of a way to measure the temperature of the phone (when you overclock/or even normally) ?
My phone does heat up sometimes

For over/underclocking there must be support for it built in kernel ! So if stock kernel doesn't support it you cannot probably change frequencies without changing kernel on stock Rom !
Also read the kernel's documentation - stable frequencies will be listed there - jumping back and forth these frequencies won't cause any troubles apart from the obvious battery drainage depending on your settings

Sianspheric said:
Hi guys,
I've got a Galaxy S3 via Rogers, rooted, running the rom Triune II, I haven't messed around with custom Kernals (tbh haven't figured that out really), I recently installed SetCPU to overclock my S3 for running graphic intensive/slow loading games like Asphalt 7, etc.
So far for that purpose it's been amazing, the games literally open twice as fast. I've setup SetCPU for a variety of CPU changes, ie. higher speeds for graphic intensive games, lower speed for screen off while charging (ie. overnight) and it seems to be working great.
My questions are:
Can "overclocking" damange my device? Ie. I know that obviously overclocking shreds through battery life, but is playing a game at the top speed available on SetCPU (1512 Mhz) bad over a prolonged period?
Also, am I not reaping the full benefits of over/underclocking having a custom kernal installed?
Also...nother totally n00b one, if the S3 is capable of reaching the "overclocked" max speed, why doesn't it in the stock ROM? I just don't quite get that....is it because the battery life would be terrible and people would blame Samsung for it?
Click to expand...
Click to collapse
Yes overclocking can damage your cpu from overheating, some even believe it may reduce the lifespan of you cpu.
If you are running 1512 max you are running stock mhz, that isn't overclocked. You cannot run a stock Sammy kernel and overclock it unless it's been recompile..to be overclocked.
I recommend ktoonsez kernel it can be overclocked to 2106mhz and underclocked to 96mhz. As well as undervolting support which is pretty much essential for overclocking because an undervolt will make your phone produce less heat by lowering the voltage your phone requires when running.
To answer your second question, yes you are not reaping any benefits without a custom kernel, this is evident.
To answer the last. The stock kernel is maxed at 1512 because that is the best mhz for the STOCK Sammy kernel performance and battery wise. Also its possible that overheating happened when they set the max at higher mhz during their tests.
Some good general knowledge if you decide to overclock, would be learning how to and what undervolting does for your phone. You can read up on that here:
http://forum.xda-developers.com/showthread.php?p=33282284
Ktoonsez kernel thread: http://forum.xda-developers.com/showthread.php?p=28399829
Make sure you download the right one for your rom!
If after reading about undervolting and installing kernel and would like some safe undervolting and gov/scheduler settings let me know! You can also find many other settings here:
http://forum.xda-developers.com/showthread.php?p=31539830
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Sorry that kernal thread is a bit confusing.
Does that Kernal only exist for the stock carrier ROM and CM?
I'm using Triune II, if the kernal doesn't exist for that ROM then I take it I have to change ROM's?

Sianspheric said:
Sorry that kernal thread is a bit confusing.
Does that Kernal only exist for the stock carrier ROM and CM?
I'm using Triune II, if the kernal doesn't exist for that ROM then I take it I have to change ROM's?
Click to expand...
Click to collapse
No. Triune is a TW based ROM. Therefore, you need to download KToonsez TW kernel. Keep in mind there is a ICS TW kernel, and then there is a JB TW kernel.
There are other kernels out there. Faux123 has a good one. It is capable of OC to 1.8Ghz, I believe.

Sianspheric said:
Sorry that kernal thread is a bit confusing.
Does that Kernal only exist for the stock carrier ROM and CM?
I'm using Triune II, if the kernal doesn't exist for that ROM then I take it I have to change ROM's?
Click to expand...
Click to collapse
Download the one titled touchwiz and whatever version you are running be it ice cream sandwich touchwiz, or jellybean touchwiz.
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