I'm interested in underclocking/overclocking my S3 to save battery life primarily. I understand that underclocking is different than using a CPU governor. What is the difference exactly?
Also, is it possible to underclock using the CM10 nighties? I understand that underclocking is dependent on the kernel you use. Does the standard CM10 kernel have this capability? Or does anyone know if its possible to get another kernel that CM10 is compatible with that has the capabilities to underclock?
thanks!
This thread would be a good place to start reading.
http://forum.xda-developers.com/showthread.php?t=1369817
Related
I'm using this kernel as packaged with oxygen 2.0.1 and I'm interested to learn more about how it manages the CPU and what voltage it uses. Done a fair bit of Google and not finding much!
What is the min and max cpu frequency it allows?
Does it scale between these automatically?
What voltage does it define for the cpu; does that vary?
Is it an overclocked or undervolted kernel?
Does anyone use setcpu with this kernel and what are the effects?
All for interest only really, very pleased with rom, battery life and phone speed as is!
Full kernel is 2.6.37.2-thalamus-S-gfbbb1325thalamus @ozone#1,
look forward to comments!
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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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).
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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.
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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.
been looking through a lot of kernels and Roms, anyone have any particular ones they prefer and why? bit of help on mix and match.
thanks
Stock, or stock voltage and overclocked.
The kernel handles voltages better than manual users do. The rest of the stuff is mostly fluff.
I'm running codename rom at the moment, overclocked to 1.3 ondemand, changed nothing else, didn't go near voltage settings, but mostly just run it stock
adrynalyne said:
Stock, or stock voltage and overclocked.
The kernel handles voltages better than manual users do. The rest of the stuff is mostly fluff.
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So undervolting and hotplug aren't really beneficial for improving battery life?
I was running morfic's trinity kernel. you can find the thread here
I've noticed that my S3 gets hot quite often and am considering to undervolt my Galaxy s3.
Does undervolting interfere with the performance of the S3? I am the type of user who HATES when there are lags when you scroll through pages, homescreen, and app drawer.
Undervolting is just lowering how much voltage a given frequency uses. It doesnt effect tye performance. The only thing you need to be careful of is instability. Not all chips can undervolt the same. If you undervolt too much for your chip you will get freezes and reboots.
Sent from my Galaxy S3 running DietICS
PMentior said:
Undervolting is just lowering how much voltage a given frequency uses. It doesnt effect tye performance. The only thing you need to be careful of is instability. Not all chips can undervolt the same. If you undervolt too much for your chip you will get freezes and reboots.
Sent from my Galaxy S3 running DietICS
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That is exactly right. I have two S3 phones on the FAUX Kernel .10u Version and one can under volt to 800 for min frequency and the other will not boot with these settings. Through trial and error both are stable but voltages are different.
PMentior said:
Undervolting is just lowering how much voltage a given frequency uses. It doesnt effect tye performance. The only thing you need to be careful of is instability. Not all chips can undervolt the same. If you undervolt too much for your chip you will get freezes and reboots.
Sent from my Galaxy S3 running DietICS
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Thanks for the reply. Could you tell me what Kernel / Governor settings and how much i should undervolt to get a stable setting?
It would be great if the performance was still there while saving battery.
rnehrlf said:
Thanks for the reply. Could you tell me what Kernel / Governor settings and how much i should undervolt to get a stable setting?
It would be great if the performance was still there while saving battery.
Click to expand...
Click to collapse
I use this kernal : http://forum.xda-developers.com/showthread.php?t=1756776
Things to know about the kernal:
-If you are using a stock based rom use the sammy version.
-You need to reflash the kernal after any rom flash or you lose wifi/bluetooth
The kernal is already undervolted a little. If you want more you need to do some trial and error to find what works for your chip.
PMentior said:
I use this kernal : http://forum.xda-developers.com/showthread.php?t=1756776
Things to know about the kernal:
-If you are using a stock based rom use the sammy version.
-You need to reflash the kernal after any rom flash or you lose wifi/bluetooth
The kernal is already undervolted a little. If you want more you need to do some trial and error to find what works for your chip.
Click to expand...
Click to collapse
Thank you so much. And which app would i use to change the clockspeed and governor settings?
So that kernel will work with stock Bell rom? If i dont like the kernel, can I just reload my previous nandroid image to remove it?
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
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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.
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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.