Surely it makes little difference on a processor with dynamic clk freq scaling?
Assuming its always clocking at its slowest during idle, which your phone is by default, then reducing the max clock speed during activity just extends the time its chugging away at max speed.
Only way to improve battery life is to reduce the amount of work you ask of your phone, not the speed at which it gets on with it.
For example, if my Desire has to process an image, it can either do that in 1ms at 1GHz, or 2ms at 500MHz, using the same amount of battery, no? At all other times its idling at the same 250MHz.
So the way forward is to reduce tasks, not underclock? And if anything the profile conditions in SetCpu are just one more thread.
Anyone actually noticed better battery performance from SetCpu?
I noticed bader Battery Life! So i dont use it anymore!
I don't think it will give you more battery life to reduce the cpu speed. more important i think is to watch the tasks that run on the background. some apps can drain you battery really fast. i just use advanced task killer and set it to kill apps when i turn my screen off, for me it helps more then lower the cpu speed.
Those apps drain battery by not letting the cpu idle, hence lowering max speed could improve battery life.
Sent from my HTC Magic using XDA App
Can someone point me to where I can learn how to use set cpu and set voltage properly. Just installed superotimized kernel and wondering how to take full advantage of it
p4ranoid4ndroid said:
Can someone point me to where I can learn how to use set cpu and set voltage properly. Just installed superotimized kernel and wondering how to take full advantage of it
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overclocking is pre-enabled, under volting can be done through an app the link is in the thread. there are 2 settings. try about -50v each if that works fine bump one down to -75mv at a time. test the phone over a day or two and see how it runs, see if it has sleep death after a few periods of inactivity, especially extended periods, see if it has sleep death while charging, which seems to make a difference that will test the low setting.
see if the phone shuts down without freezing, and see if it shuts down without freezing while charging, the heat in the battery makes a big difference, play some 3d games. if you have freezing issues you can disable overclocking under different situation with set cpu or se t the volts to a more conservative setting.
Dani897 said:
overclocking is pre-enabled, under volting can be done through an app the link is in the thread. there are 2 settings. try about -50v each if that works fine bump one down to -75mv at a time. test the phone over a day or two and see how it runs, see if it has sleep death after a few periods of inactivity, especially extended periods, see if it has sleep death while charging, which seems to make a difference that will test the low setting.
see if the phone shuts down without freezing, and see if it shuts down without freezing while charging, the heat in the battery makes a big difference, play some 3d games. if you have freezing issues you can disable overclocking under different situation with set cpu or se t the volts to a more conservative setting.
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Click to collapse
I've been told that undervolting can improve the battery time. Of course, lots of varying opinions of how good/bad it may be to overclock.
If I want to just undervolt, is that possible with SetCPU?
Dani897 said:
overclocking is pre-enabled, under volting can be done through an app the link is in the thread. there are 2 settings. try about -50v each if that works fine bump one down to -75mv at a time. test the phone over a day or two and see how it runs, see if it has sleep death after a few periods of inactivity, especially extended periods, see if it has sleep death while charging, which seems to make a difference that will test the low setting.
see if the phone shuts down without freezing, and see if it shuts down without freezing while charging, the heat in the battery makes a big difference, play some 3d games. if you have freezing issues you can disable overclocking under different situation with set cpu or se t the volts to a more conservative setting.
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Click to collapse
ewingr said:
I've been told that undervolting can improve the battery time. Of course, lots of varying opinions of how good/bad it may be to overclock.
If I want to just undervolt, is that possible with SetCPU?
Click to expand...
Click to collapse
Interesting stuff...
I too would like to know if it is possible to simply under-volt. Does anyone know the optimal settings for SetCpu with the Captivate...or does it vary depending on each users profile/ phones?
So Ive been playing around with various settings for set cpu and voltage control and all has been well so far. The only problem im having is voltage control seems broke. I try to open the all but it just black screens. I tried to clear the memory and unistall and reinstall and still have the same problem. Any ideas?
http://forum.xda-developers.com/attachment.php?attachmentid=432086&d=1288709102
^you can under volt setirons kernel and disable overclocking with this app.
i find my battery life to be less than stock with this kernel, i need to see if it is a common issue, maybe because it is not a captivate kernel. but in the past with unhelpfuls kernel for 2.1 battery life was awesome.
spartan062984 said:
Interesting stuff...
I too would like to know if it is possible to simply under-volt. Does anyone know the optimal settings for SetCpu with the Captivate...or does it vary depending on each users profile/ phones?
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Click to collapse
It's going to depend on the individual CPU in your phone. Your best result is to start at a given clock speed and begin lowering voltage in the smallest step possible, test for stability, repeat until you begin to notice instability (or you just run out of voltage options). You can just undervolt without increasing clock speed any, or you can not undervolt yet raise clock speed, or you can overclock and undervolt, depending on how your particular chip reacts. Some might need additional voltage to stabilize the snapdragon at 1.2Ghz while others (mine for example) is stable Able @ -100mV and 1.2Ghz. Overclocking silicon is the ultimate in YMMV.
Another thing to bear in mind is that increasing clock speed necessarily increases power consumption. There is no way around this. So a chip at 1.2Ghz will use more juice than 1Ghz even with the same voltage. It's difficult to say at this point whether, say, the Snapdragon @ 1.2Ghz and -100mV uses more or less power than the same chip @1Ghz and stock voltage. It's absolutely possible that the former uses more power, which would explain why you see at least one claim here of battery life decreasing even when voltage settings are left untouched.
hawkeyefan said:
It's going to depend on the individual CPU in your phone. Your best result is to start at a given clock speed and begin lowering voltage in the smallest step possible, test for stability, repeat until you begin to notice instability (or you just run out of voltage options). You can just undervolt without increasing clock speed any, or you can not undervolt yet raise clock speed, or you can overclock and undervolt, depending on how your particular chip reacts. Some might need additional voltage to stabilize the snapdragon at 1.2Ghz while others (mine for example) is stable Able @ -100mV and 1.2Ghz. Overclocking silicon is the ultimate in YMMV.
Another thing to bear in mind is that increasing clock speed necessarily increases power consumption. There is no way around this. So a chip at 1.2Ghz will use more juice than 1Ghz even with the same voltage. It's difficult to say at this point whether, say, the Snapdragon @ 1.2Ghz and -100mV uses more or less power than the same chip @1Ghz and stock voltage. It's absolutely possible that the former uses more power, which would explain why you see at least one claim here of battery life decreasing even when voltage settings are left untouched.
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Thanks for clarifying Hawkeye! I will report back on in a few days once i have tested out a few profiles. In my opinion, I feel that it is best to leave Over-clocking at default and maximize battery utilization with setcpu. However, the thought of over-clocking the Dragon beast is VERY tempting. Who wouldn't? I will definitely check out the differences when playing games and such.
spartan062984 said:
Thanks for clarifying Hawkeye! I will report back on in a few days once i have tested out a few profiles. In my opinion, I feel that it is best to leave Over-clocking at default and maximize battery utilization with setcpu. However, the thought of over-clocking the Dragon beast is VERY tempting. Who wouldn't? I will definitely check out the differences when playing games and such.
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Click to collapse
I have to tell you, I'm not personally very fond of SetCPU on this device, even though I paid for the app (ugh). With raspdeep's voltage control app and SetIron's OC/UV kernel, the CPU defaults to 1.2Ghz at stock voltage, which for a basic setup is fine. Voltage Control app is phenomenal for adjusting in increments of 25mv at a time...one setting is for high clocks (1Ghz - 1.2Ghz) and the other is for < 1Ghz. It's probably best actually to start with the lower clock setting in Voltage Control, as your phone will spend the lion's share of it's time at those clocks and so that is where you should see the most gain in battery life. My only gripe is that I can't get the boot settings to stick on the Captivate so I have to go in and adjust them each time I reboot the phone. no biggie there.
SetCPU, on the other hand, has caused me loads of problems in the past, including causing the phone not to wake up from sleep and just atrocious battery life, I assume from constantly polling the CPU clock to measure clock speed. I have not experienced any of that with Overclock Widget, but I also don't use any of the independent clockspeed controls in the app...basically it's just a widget to display clock speed the way I use it. Otherwise, Setiron's kernel gives the 200mhz overclock and I just let the Hummingbird deal with changing clocks on its own. Jmo, but it works for me with no resulting battery drain beyond the additional I expect as a result of the extra 200mhz.
edit: whoops, long day. hummingbird in my post from above, not snapdragon. I need a drinky poo.
hawkeyefan said:
I have to tell you, I'm not personally very fond of SetCPU on this device, even though I paid for the app (ugh). With raspdeep's voltage control app and SetIron's OC/UV kernel, the CPU defaults to 1.2Ghz at stock voltage, which for a basic setup is fine. Voltage Control app is phenomenal for adjusting in increments of 25mv at a time...one setting is for high clocks (1Ghz - 1.2Ghz) and the other is for < 1Ghz. It's probably best actually to start with the lower clock setting in Voltage Control, as your phone will spend the lion's share of it's time at those clocks and so that is where you should see the most gain in battery life. My only gripe is that I can't get the boot settings to stick on the Captivate so I have to go in and adjust them each time I reboot the phone. no biggie there.
SetCPU, on the other hand, has caused me loads of problems in the past, including causing the phone not to wake up from sleep and just atrocious battery life, I assume from constantly polling the CPU clock to measure clock speed. I have not experienced any of that with Overclock Widget, but I also don't use any of the independent clockspeed controls in the app...basically it's just a widget to display clock speed the way I use it. Otherwise, Setiron's kernel gives the 200mhz overclock and I just let the Hummingbird deal with changing clocks on its own. Jmo, but it works for me with no resulting battery drain beyond the additional I expect as a result of the extra 200mhz.
edit: whoops, long day. hummingbird in my post from above, not snapdragon. I need a drinky poo.
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LOL. No Worries. I myself made the same mistake. I thought something was odd with my post. SnapDragon...Hummingbird....Bulbasaur.....I knew what you meant. lol
Still not having any luck with the voltage control app. Ive tried flashing different roms to see if it would work. I undervolted it to 100/75 the first time i did it and now i cant change. Only a little worried
i guess there was an issue with the set on boot scripts not working. supposedly that is fixed, i dont know for sure though, i haven't updated.
From what I'm gathering, in order to undervolt, you must have a kernel to su pport that, for example Setirons.
I'm not necessarily interested in overclocking, as it performs well as is. Of course there are arguments that overclocking may ultimately harm the phone, and arguments that by the time that happens, you'd be ready for a new phone. In any event, if I start getting slower, I may interest in overclocking.
Does anyone know if dramatic improvement in battery performance with underclocking?
I've noticed quite a bit of a difference, just pretty difficult to tune it precisely. (Coming from a person who enjoys overclocking computers a little too much). I just wish there was an app that would test each frequency and then let you know which one failed (without having to manually set it).
I am playing a bit with underclocking my DS (Using UNITY v4 kernel atm, will update to v9 later).
However, I'm figuring out the usefulness of it (to extend battery life mainly).
Does it really save battery life? I'm already using JuiceDefender, and its SetCPU function.
Or is it not very useful since the most batterydrain comes from radios anyway.
What are the best values for it?
What's the standard clockspeed for the DS? And what is the best Max IDLE clock speed?
Well, i wont underclock at all.
First of all there is no need to do that to get good battery life. You can do lot other stuff to do so.
Under-clocking is risky as it might now have enough power that needed to the phone. that means that some stuff might not get processed like calls and stuff.
Right now with me using miui i get life for about 3-4 days.
Standard clock speed is 1,000mhz.
I have mine underclocked to 600mhz during idle times and it's perfectly fine.
Never had any issues at that speed and it keeps my Desire S much much cooler which can only be a good thing.
As for it's ability to extend the battery, I don't think it does so much in my case. I typically run WiFi overnight and G/3G/H during the day and my display usually chews up 60-70% of my overall battery usage even on a very dark screen.
I'd pick a setting that you feel comfortable with but have low expectations of the benefits.
The only time I use underclocking is for using Google Navigation.
On a hot day using Navigation for over a couple of hours, my DS would over-heat and restart (usually as I was approaching my motorway exit). So I have Tasker dialing back CPU to 768Mhz when using Navigation, and it does seem to help the phone run a little cooler. I no longer have to take it out the case for example.
Using the smartass governor (I believe) automatically knocks the CPU back to 240Mhz when sleeping. Not 100% on that though.
I'm currently testing a new kernel, and I spent an entire charge cycle on 'Smartass' and then an entire charge cycle on 'Powersave'. Aside from lots of lag on the latter one, the battery life was pretty much the same!
So recently I've become too lazy to constantly charge my Captivate and began to experiment with undervolting/underclocking it. Has anyone found optimal voltage for battery life? I've currently got every step of 200mhz down 100 volts and underclocked to a max of 800mhz. I'm on Semaphore kernel 2.9.5sc.
freshlimes said:
So recently I've become too lazy to constantly charge my Captivate and began to experiment with undervolting/underclocking it. Has anyone found optimal voltage for battery life? I've currently got every step of 200mhz down 100 volts and underclocked to a max of 800mhz. I'm on Semaphore kernel 2.9.5sc.
Click to expand...
Click to collapse
There isn't a optimal setting as all phones act different. Testing is the best you can do.
which cpu governor are you running? that may have more effect than underclocking/undervolting on battery life.
user Stempox has a nice post on cpu governors here
http://forum.xda-developers.com/showthread.php?p=28647926
the screen on time and data/gps traffic, and apps that keep the phone awake, do more to effect power drain than other factors. so, if you manage those, and choose the governor that suits you preferences, then undervolting and underclocking aren't needed, IMHO.
you can tweak the governor settings with Semaphore manager, if you really want to do that too.
the thing is, you may end up keeping the screen on longer than you would at higher cpu speeds, which would counter any battery savings. also, undervolting can increase the error rate, which means further delays while phone is awake.
hope this is helpful in your pursuit of fewer charging cycles.
Sent from my SGH-I897
Hello guys
I'm not a new user in kernels or ROMs .
I have a low-decent battery life ,and I'm sure there's a way to get a better battery life with undervolting .
I want to know
what is "undervolting" ?
What is the biggest damage it can cause?
What is PVS?
How do I know ,how much I can UV?
What are the steps to undervolt?
What I gain from UV (despite battery life)?
For your info ,I'm using AOSPAL ROM +FAUX's latest 16u kernel .
Thanks
Sent from my Nexus 5 using XDA Premium 4 mobile app
http://forum.xda-developers.com/showthread.php?t=2537000
Sent from my Nexus 5 using Tapatalk
Hi,
Most of your questions have a reply:
About undervolting: http://forum.xda-developers.com/google-nexus-5/general/nexus-5-undervolting-thread-t2537000.
CPU binning: http://forum.xda-developers.com/google-nexus-5/general/cpu-binning-nexus-5-t2515593.
The "risks" are instability like hard reboot, SOD, etc.... To find a "safe" value you will need to test by yourself to find what undervolting your CPU can handle, not all CPU's are equals.
Undervolt by steps like - 25mV, don't set your new values at boot unless your are sure it's stable (or you could encounter bootloop), test for a few days under different conditions (as your use).
The gain apart battery life (but you will not gain that much as people tend to think) is a little less heat, but again nothing huge..., better is to test by yourself and see what you will gain... or not.
Battery life depends mainly of your use, apps, signal quality and settings like, screen brightness, synchro, CPU governor, etc... In my opinion check first what could be the cause of your low battery life (and what is low battery life for you???) before play with undervolting.
As said above, undervolting will get you very minor battery life increases.
More than likely you have an issue, or its just your setup and usage giving you the battery life you are seeing.
Undervolting will not change any of this.... You'll gain only minutes of battery time.
Try some troubleshooting in the below thread to see if you have an issue, or how to setup for better battery life. Read through it a bit, from the last page and work back a bit. You can post meaningful screenshots there too. From gsam or BBS.... not the stock battery screen, it has no real useful info for finding issues. Good luck!!
http://forum.xda-developers.com/showthread.php?t=2509132
Nexus 5 Battery Results
I've been undervolting many systems for many years, primarily Linux desktops and some servers, and the primary benefit is that you get less heat output which means when running cpu-intensive tasks the temperature climbs slower so the throttling of the clockspeed kicks in later, so your phone will be faster in certain situations. If you take a phone which has been idle for a while and run a benchmark, and then immediately run that benchmark again, the 2nd time gets a lower result as the phone is still hot from the 1st. This makes drawing conclusions about settings really dificult but it illustrate that throttling from heat is affecting speed.
For most users their perception will be the phone runs cooler.
You do undervolt at each step in the processor's frequency, and each step is a trial+error activity, the throttling I mention means finding a stable under-volt at the higher frequency which is labour-intensive,i.e take the max clock, and undervolt it a little, run a benchmark which forces it to run at high clockspeed, and if it passes that test then run it again at the next step down in frequency. Once you've got the most stable top clockspeed, then do it progressively for all the other voltages on the way down.
In some platforms in Linux and Windoze, we wrote scripts which save the stable voltages and then undervolts a little and runs a stress-testing benchmark and if the system hung it wouldn't save the current voltages so the previous higher voltages were safer, stick that script in a startup script area and leave the compute to do many self resets, and you've calculated your device's voltage range. I wonder if someone has that done for Android??? For a laptop the FAN would run slower saving battery time and for laptops that would lead to say 20% better battery life but on a phone it won't make much saving as no fan.
Your phone will run most of its time (like 95%) at its lowest frequency, so for effort/benefit just focusing on dropping its voltage will gain the most in the phone running cooler.
Battery life improvement is marginal, if you look at your battery stats its down to your application settings and screen brightness, i.e. how you use and what you do with your phone. So if your battery life is bad, use your phone less!
I carry a slim USB battery, it is the $/effort/benefit the best thing you can do, $20 doubles your battery life, if you get one with a 1.5A-2A output in just a few minutes when the phone doesn't mind a battery attached, will dwarth every possible tweak and hack anyone can form in benefit.