Develop Bugs

[Q] what exactly is undervolting

i have used the search and not found any solid info
what are the benefits of it if any

I haven't heard of people undervolting their fone, although i haven't looked to much.
This would mean though reducing the power that the CPU gets. I would imagine this increases battery life among other things.

Your right about what it is, but almost every custom rom/ kernel is undervolted in development section.
Sent from my HTC Desire using XDA App

Undervolting means, the CPU (or hardware in the phone) gets lower voltages, thus saving more battery & not loosing performance.
Undervolting is a process which reduces the excess "voltage" given to the CPU using a software. This is widely used as a cooling solution and in my opinion more effective than any other cooling solution available (thermal paste, cooling pad, etc) at NO cost. Undervolting will NOT compromise performance at all. Underclocking and Overclocking (clock speeds) is whats responsible in regards to performance. Benchmarks will also prove that performance remains the same.
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Not excess voltage but fully, manufacturer guaranteed, stable Core voltage to lower guesswork voltages which may or may not work and may or may not cause data loss/corruption.
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- Sent via HTC Desire -

A cpu needs power for every 'clock cycle'. 1Ghz means there are a billion per second. IF you lower the voltage, there is less power used. But if you lower it too much, the cpu wo'nt be able to 'cycle its clock'...
So undervolting doesn't affect performance, since the cpu remains on 1Ghz. It decreases the power used, so you get better battery life.
Every single cpu is different, so HTC has chosen a default voltage that (shoud) work on all phones they sell. But your particular cpu could be able to work at a lower voltage. It's just a matter of trail and error. Decrease the voltage until the cpu stops working, then higher it a bit. That way you've undervolted your cpu so it uses the least power.

koenvbeek said:
A cpu needs power for every 'clock cycle'. 1Ghz means there are a billion per second. IF you lower the voltage, there is less power used. But if you lower it too much, the cpu wo'nt be able to 'cycle its clock'...
So undervolting doesn't affect performance, since the cpu remains on 1Ghz. It decreases the power used, so you get better battery life.
Every single cpu is different, so HTC has chosen a default voltage that (shoud) work on all phones they sell. But your particular cpu could be able to work at a lower voltage. It's just a matter of trail and error. Decrease the voltage until the cpu stops working, then higher it a bit. That way you've undervolted your cpu so it uses the least power.
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Very sensible answer..Thanks

koenvbeek said:
A cpu needs power for every 'clock cycle'. 1Ghz means there are a billion per second. IF you lower the voltage, there is less power used. But if you lower it too much, the cpu wo'nt be able to 'cycle its clock'...
So undervolting doesn't affect performance, since the cpu remains on 1Ghz. It decreases the power used, so you get better battery life.
Every single cpu is different, so HTC has chosen a default voltage that (shoud) work on all phones they sell. But your particular cpu could be able to work at a lower voltage. It's just a matter of trail and error. Decrease the voltage until the cpu stops working, then higher it a bit. That way you've undervolted your cpu so it uses the least power.
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How would one go about under volting .i have tried everything suggested to me and nothing really seems to make a difference
Sent from my HTC Desire using XDA App

Most kernels are undervolted and unless you can compile the kernel for yourself you are stuck with the values given by the creator. There are two exceptions for this, HAVS kernels which automaticly chose a voltage depending on temperature and some other stuff and SVS kernels with snq-'s volt selection interface (found in Leedroid and maybe some other kernels/roms).
So what exactly have you tried and what did you expect to see? Because the difference won't be that noticeable.

TheGhost1233 said:
Most kernels are undervolted and unless you can compile the kernel for yourself you are stuck with the values given by the creator. There are two exceptions for this, HAVS kernels which automaticly chose a voltage depending on temperature and some other stuff and SVS kernels with snq-'s volt selection interface (found in Leedroid and maybe some other kernels/roms).
So what exactly have you tried and what did you expect to see? Because the difference won't be that noticeable.
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I have tried battery calibration, using app watch dog to let me know which apps are using excessive CPU. Putting my brightness down to 10%, making sure not everything is synced, the only thing synced is beautiful widgets every 4 hours. And just about everything else that has been put forward to me. Here's another example I just taken my phone off charge at 100% and wrote this and I'm now at 73 %. And its only taken2 mins to write
Sent from my HTC Desire using XDA App

adz63 said:
I have tried battery calibration, using app watch dog to let me know which apps are using excessive CPU. Putting my brightness down to 10%, making sure not everything is synced, the only thing synced is beautiful widgets every 4 hours. And just about everything else that has been put forward to me. Here's another example I just taken my phone off charge at 100% and wrote this and I'm now at 73 %.
Sent from my HTC Desire using XDA App
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So in short you havent tried any kernel with undervolting at all!

Well that all has nothing to do with undervolting, but (extra) undervolting will not fix the drain problem you have.
Do you use setCPU cause your sig says you run at 1113MHz, which cause higher consumption. Also did you set your wifi sleep policy to never(setting-wireless and network-wifi settings-press menu-advanced-wifi sleep police).

At the moment I have the havs kernel that comes with oxygen 2.0 rc6. I have posted another topic about is the kendal good for battery life etc and no1 has told that another kendal would make anything better
Sent from my HTC Desire using XDA App

TheGhost1233 said:
Well that all has nothing to do with undervolting, but (extra) undervolting will not fix the drain problem you have.
Do you use setCPU cause your sig says you run at 1113MHz, which cause higher consumption. Also did you set your wifi sleep policy to never(setting-wireless and network-wifi settings-press menu-advanced-wifi sleep police).
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@TheGhost1233, how exactly does one decide which kernel suits us best..
Eg: I see two undervolted kernels (I think) at 875 and 925 mV. I have no idea how to decide. Trial and error?
Froyo Kernel [email protected] min
Froyo Kernel [email protected] min

@droidzone Yes trial and error. The mentioned voltage is the lowest the cpu will get at 245MHz. Not all devices are stable with 875mV (you will know if your phone freezes up) so then you move up to the 925mV min. Other than the voltage there is no difference between 875mV or 925mV.
With the HAVS kernels it can take a while before you notice the freezes cause the voltage is dynamic, so be careful if you need your phone as a alarm clock.

[Q] Is it really safe to keep overclocking to 1GHz?

I am new to android phones. And i have no experience about overclock.
Will my cpu easily break down due to keep overclocking?..
Honestly, i seldom change my cell phone model, i want my defy can stay a life at least 1.5yr.

i think overclocking can't really damage your phone, voltage can. so i suggest you keep the voltage around [email protected] (default is [email protected], so this should be fine), and if the phone doesn't hang or reboot, you're good to go but you could try lowering vsels, you know, the lower the voltage, the lower the power consumption, the heat and the chance to fry your cpu but i'm not sure!

Yep, 1 GHz is safe, I'm using [email protected] as well, and the CPU is capable to run easily at [email protected] continuously. The leaked Gingerbread ROM from Motorola uses 1GHz as well, so don't worry, you just have to find the safe vsel settings.

thanks for replying, i m currently using 1GHz @ 58 .. Everything is alright
Should I make the voltage as low as possible?

yeah, just to lower the power consumption and temperature, but it isn't necessary.

Can you share your voltage setting please..?
I do the stability test and it gets successful run for 5min then this means the setting is okay?

i don't overclock, just undervolt, here are my settings (with setvsel):
800MHz - 45vsel
600MHz - 30vsel
300MHz - 18vsel
up_threshold: 90%
actually if you wanna make absolutely sure your device is stable, you should run it like for an hour. but if it runs for 5 minutes without error that's quite okay, you shouldn't have problems with those settings

Thanks so much, i m trying to lower my voltage setting.
Besides, i want to ask about the battery temperature, what is the maximum temperature before getting damage to the cell? I usually goes up to 37~39 degree celsius.. is it normal?

mine is usually around 29-32 °C, but i have it undervolted, so idk. but 37-39 seems a bit high, that means the cpu temp is way over 40 degrees, you should check it out!
EDIT: tried stress testing for 20 minutes with [email protected], it went up to 35°C, so you should definitely find out what's wrong with your device!

I actually underclocked to 600MHz, since I couldn't see a big difference even at 1200MHz in normal usage. A Pentium3 at 4Ghz will still not perform as well as a slower clocked new CPU for example, CPU design is more important - what instructions it supports.
Battery life is more imprtant to me and heat is very bad for Li-ion batteries too.
Also I found changing the CPU governor to "interactive" made a difference in GUI responsiveness and I have had less stuttering.

nisamtetreb said:
I actually underclocked to 600MHz, since I couldn't see a big difference even at 1200MHz in normal usage. A Pentium3 at 4Ghz will still not perform as well as a slower clocked new CPU for example, CPU design is more important - what instructions it supports.
Battery life is more imprtant to me and heat is very bad for Li-ion batteries too.
Also I found changing the CPU governor to "interactive" made a difference in GUI responsiveness and I have had less stuttering.
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so, what's your standby lifetime after underclocked cpu?

I can see the performance improved when i was watching flash video on browser. But honestly, i dont think there are anymore huge difference after overclocking..
But as the battery life still remains quite well, i will still keep overclocking to 1GHz.. Isn't it a good idea?

nisamtetreb said:
I actually underclocked to 600MHz, since I couldn't see a big difference even at 1200MHz in normal usage. A Pentium3 at 4Ghz will still not perform as well as a slower clocked new CPU for example, CPU design is more important - what instructions it supports.
Battery life is more imprtant to me and heat is very bad for Li-ion batteries too.
Also I found changing the CPU governor to "interactive" made a difference in GUI responsiveness and I have had less stuttering.
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lol... What happend to HD and THD games... Did u try playing them at 600mhz??

Overclocking to 1 GHz with the right voltage values seems to be absolutely no problem for Defy.
BTW, does anyone know whether it's possible to set scaling governor to "Interactive" mode under Froyo? Gingerbread kernel let me set it, but I haven't found the way under Froyo.

Battery life was a little bit better, the display and 3G always draw a lot of power.
Standby time got better, but I don't use very low vsel any more due to errors in YouTube and dropped connection of radio streams.
Before I used 300-600-800 at 20-30-48, this was very stable in stability test, but for example Youtube would start showing "error playing video". After I increased vsel, it went away.
I mostly did it to lower temperature, optimal temperature for li-ion is around 25°C according to Wikipedia I think.
I don't play 3d games, they would benefit the most from overclock I believe.
Angry birds RIO for example would stutter for a second or two after a level loaded, but it would become as smooth as at higher clocks, when I wait for a second.
I hope flash gets better, when hardware acceleration gets enabled in Quarx's CM7.

I was running [email protected] for a month straight. No issues at all. The highest my temp reached was 112F after playing games for about an hour straight. I now just run it at [email protected], and it's plenty fast for me. I did some "testing" with all the options in SetVsel. It's not science sound, but if you use the Gingerbread Icon in the notification bar, and are running at stock (800 speed) you will notice when the CPU maxes out it doesn't even reach full capacity. I found Words with Friends to really use the CPU, and at 800 it pings the meter in the orange (The notification icon shows green, orange, and red for "zones"). If I overclock it at 1000 or above then the meter goes into the red. I don't know the exact number it switches from orange to red, but being at stock 800 is well below what the chip can really do since it doesn't even max out the meter. I hope I didn't confuse anyone. It makes sense to me.

weird...my cpu at any game reach the 800mhz
yet even in normal situations like browsing through the files on the phone it reaches 800mhz
and also despite the values i use in setvsel are not high(which is:
24 @ 300
34 @ 600
48 @ 800
)
the phone still reaches maximum 38C when i play games and if i set the value in the third vsel the games starts to hang!!
seems like i am the only one who have these problems..but why
anyone have any idea
im running stock arabic froyo btw
if someone can confirm to me that i can keep Arabic language if i installed another rom using custom restore in nandroid then i would be using prays or official 2.3 but no one answered me about that
anyway the important thing is anyone knows why my cpu temp is always high?

Well ambient temperature is important too. If it is 30°C where you live and your phone's temperature is at 35°C I'd say you are good. If the outside temperature is 10°C and your phone is dat 40°C I'd say there is something wrong (unless you were playing games or watching a movie).

in my opinion, it is definitely safe that you overclocking to the leaked moto level.
however, the voltage is still a mystery.
there's no constant conclusion about this.
i'm using [email protected], [email protected], [email protected], and it works fine for me

I'm getting really annoyed. No problems clocking up to 1100mhz with stock voltage (58). But changing the voltage settings, even slightly, makes the phone more or less unstable.

[Q] Setting clock speed to 800 -1200 mhz?

I know unrooted desire z devices always work at 800mhz. My device is set to 245mhz min and 1400mhz max (interactive or smartass governor). It sometimes causes my device to wake up a bit late. I wonder how long time my battery goes if I set my device at min 800 mhz and max 1200 or 1400 mhz... Did anyone try this clock speeds?

Deadly Sto(R)m said:
I know unrooted desire z devices always work at 800mhz. My device is set to 245mhz min and 1400mhz max (interactive or smartass governor). It sometimes causes my device to wake up a bit late. I wonder how long time my battery goes if I set my device at min 800 mhz and max 1200 or 1400 mhz... Did anyone try this clock speeds?
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That's way too low of a min speed, just bump it up to the next (I think it's 386) and you should see noticable improvement.
I'd also suggest the ondemand gov; since it only ramps up to the top speed when needed, then drops it back down again, you should get a bit better battery life.
Sent from my HTC Vision using XDA App

OriginalGabriel said:
That's way too low of a min speed, just bump it up to the next (I think it's 386) and you should see noticable improvement.
I'd also suggest the ondemand gov; since it only ramps up to the top speed when needed, then drops it back down again, you should get a bit better battery life.
Sent from my HTC Vision using XDA App
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i read ondemand and conservative governors are od, so using interactive or smartass are better then using others. I will try min 368 mhz but am not sure if it works...

What are you trying to accomplish by messing with the clock speed? Leave it alone at default. Performance difference is NEGLIGIBLE (bottleneck is elsewhere), and all you'll accomplish is eating the battery and burning it up with excessive heat caused by excessive clock.

dhkr234 said:
What are you trying to accomplish by messing with the clock speed? Leave it alone at default. Performance difference is NEGLIGIBLE (bottleneck is elsewhere), and all you'll accomplish is eating the battery and burning it up with excessive heat caused by excessive clock.
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First of all, I would like to thank you for your comments.
People don't do anything to access root if they don't want to mess device. I am one of them and want to have a device which both has performance and visuality. You offered me to not to change clock speeds. But we know HTC Desire Z is scheduled to work at 800mhz everytime (default). My opinion is just to set minimum clock speed to 800 mhz or something like this. If my device was burn by this clock speed, it was already dead.
Today i tried this clock speed (min 614, max 1382) and during the day it didn't heat up. Moreover, 8 hours passed, i played NFS for about 1,5 hour, made some call and 30 percent of battery left. It seems this clockspeeds doesn't cause battery drain or i couldn't feel it...
EDIT: 13 hours passes, 16 percent battery left (I made minimum 30 minutes of call)

[Q] Overclocking

How safe is it to overclock my Galaxy S II to 1.78 max and 1.78 min?
If not, what combination of max and min would be most safe but still give a noticeably boost in speed.

In theory overclocking isn't that good as is adding additional strain to the CPU than it was designed to.this will cause wear and tear faster possibly shortening the life of your phone. I would set your min much lower and place it on demand. There's no need for your CPU to be running at max all the time, set it on demand do it only runs at a faster speed when it's needed to...
PS this has been covered in other threads a search would have given you an answer oppose to starting another thread.
Sent from my SGH-T989 using XDA App

Voltage kills components, not overclocking.
You can google this and research it if you would like.

I keep mine min 810 max 1782 ondemand with setcpu.
810 is more than enough(still faster than Iphone4) to hold its own without lag when you actually start to bog it down.

I think the max itll go is 1.83ghz. in reality nothing over 1.65ish really adds anything.
Sent from my SGH-T989 using XDA App

locked mine at 1.51ghz which is plenty of fast, no throttling and no lag

Setting the min up that high will kill your battery in hours. You can over clock it by setting the max up to whatever you like. Set the min lower. Then set your governor. Overclocking will wear down your cpu faster and make it run hotter. Overvolting will do the same. I would only overclock when I need it. Normally mine is set at 1.5 for max and .3-.5 for min.

[Q] Has anyone ever underclocked One X?

So I tried to underclock my One X to around 640 MHz and it was running VERY smoothly and stable with only 2 cores active. I was using the ViperX 2.2.1 ROM and the Kernel was the no OC NCX 0.99a. The battery life wasn't bad, but has anyone tried underclocking to 1 GHz or lower? If so, how is the battery life and what kernel and ROM did you use?

With SetCPU you can change the max. CPU, but why should you? When the phone doesn't need much processor power, it just scales down by itself.
So, it already has the best underclocker there is.
Mayby you could try undervolting to save even more battery, but that means the CPU can be somewhat less steady.

im trying to get my head around UVing / UCing my HOX. is there any guide around? im trying to search through the forum but still no luck.

ricopoetra said:
im trying to get my head around UVing / UCing my HOX. is there any guide around? im trying to search through the forum but still no luck.
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underclocking means the CPU runs slower so should use less battery but slower CPU speeds also means to takes longer to preform tasks which could use more battery, check on google most places say its not worth it as that battery saved is tiny and not worth the drop in CPU performance.
undervolting however lowers the voltage that CPU uses while working this does save power and also lowers heat (less voltage less heat) but if you lower it to much then the CPU becomes unstable due to lack of power and well crashes and restarts the phone in most cases.
to get the best out of undervolting you need to lock the max CPU speed to each step (CPU speed, 300mhz, 600mhz and so on) and slower the voltage and then run a bench mark (like antutu) and see if its stable, if it is you lower the voltage again and repeat until it crashes at which point you have found the lowest voltage that the clock speed can handle so you jump up a voltage then more on to the next speed.
it takes along time but that would get you the best undervolt your phone and hardware could handle.
or you can just use the global to lower the voltage for every speed, this is much faster and much less time consuming but you don't get the most out of it.
for this you basically drop the voltage then use your phone for different things; browsing, games, benchmark and see if it crashes if not lower again till it does then go back up a step.

thanks for explaining. I'm getting some of the points that I missed Awhile ago. I guess I'm going to try the longer way of doing it.
Sent from my White HOX JB PA 2.10