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
How about battery life in Overclocked phones?
Depending on how its clocked, if your needs are speed and usability it lowers the battery life.
Though you can clock it moderate and set the "min" clock frequency down and save battery while its in your pocket.
benjamin336 said:
Depending on how its clocked, if your needs are speed and usability it lowers the battery life.
Though you can clock it moderate and set the "min" clock frequency down and save battery while its in your pocket.
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benjamin336 is absolutely right. I've also found that you have to adjust the settings differently depending on the phone.
There are threads pertaining to adjusting voltages and clocking where people describe what combinations have worked best for them.
99% of the time if you're looking to overclock you're looking for performance meaning 99% of the time you are going to have crappier battery life.
Coming from the HTC Desire, where SetCPU was the only to manage the CPU, I have developed a habit of using SetCPU with several frequency profiles and different governors for various situations. For instance, I use battery<80, <60, <40, <30, screen off, temp >40, >50, and a charging profile. For governors I use lulzactive2 for higher frequency ranges, interactive for mid range frequencies and on demand for the lower frequencies. Oh, this is all with the latest matr1x kernel.
Seeing how a lot of ROMs allow extensive controll of the CPU I was wondering if it wouldn't be more efficient to just set a min/max frequency, chose a governor, turn deep idle on (which is off while I'm using SetCPU) and leave it be.
What are your thoughts and experiences on the matter?
/// endmessage / COMPUTOR5000
profile ? that's completely unnecessary...
just set governor and min-max is enough.
we have NSTOOL, so looks like extended ROM controll also not necessary because not good enough compare to NSTOOL , but lots lots ROM has it build-in
I've never bothered with profiles. I can feel if the phone needs a break from the heat and performance is good for me with 100/1200 set and slight undervolting.
Battery life while idling won't change, only while using intensive apps, and with deep idle working and max freq screen off, music playback and the likes drains very little battery.
Try it and see, you need to be comfortable with it.
I agree with qtwrk. Profiles are, in most cases, detrimental. The following is especially true since Deep Idle was implemented: always let the CPU run as fast as possible to save energy. Sounds counterintuitive, but here's why: while lower CPU frequencies in general consume less energy PER TIME than higher CPU frequencies, the faster the CPU can finish it's job, the faster it can return to energy saving states. So in the end, reducing CPU frequency actually uses more energy... Just overclock to save values, use undervoltage to set lowest possible voltage values and go to sleep.
What's the minimum you can set the screen off max frequency so that music playback isn't choppy?
Also, is the phone always idle on screen off, or does music playback, or any other activity make the phone come out of idle, even if the screen is still off?
/// endmessage / COMPUTOR5000
zyrill said:
I agree with qtwrk. Profiles are, in most cases, detrimental. The following is especially true since Deep Idle was implemented: always let the CPU run as fast as possible to save energy. Sounds counterintuitive, but here's why: while lower CPU frequencies in general consume less energy PER TIME than higher CPU frequencies, the faster the CPU can finish it's job, the faster it can return to energy saving states. So in the end, reducing CPU frequency actually uses more energy... Just overclock to save values, use undervoltage to set lowest possible voltage values and go to sleep.
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Very good point, for exemple cpu at 1000 MHz takes 1100 juices per second and 10 seconds to finish a task, total cost 10 x 1100 (11000 ) juice
If it runs at 1200 MHz takes 1200 juices per second, same task only needs 8.34 seconds, 8.34 x 1200 (10008) juices... this isn't real just number assumption and theoretically appears that way
Sent from my Nexus S using xda premium
I agree with everything that was said here and actually posted about this very topic earlier on in the matr1x thread in regards to the lulzactive settings. People putting settings too much towards battery saving are actually not getting battery savings. They are making the CPU run longer and therefore more cycles and more power. Profiles are a bad idea too. They cause problems.
I decided to ask hear instead of creating new thread, etc.
In the amazing post of droidphile http://forum.xda-developers.com/showthread.php?t=1369817 there's an information about SGS II, that
'energetically efficient' frequency for CPU is 200 mhz
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(it's Cortex-A9).
And what about Cortex-A8 on Nexus S?
droidphile also says that on Milestone (Cortex-A8) 550Mhz is the frequency used in the calculations based on the optimal energy to run. Don't know what's the source of this info...
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.
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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
Hi,
I've a stock Nexus 5 on 6.0.1 (M4B30X) that, according to GSam Battery Monitor, has consistently high CPU usage (20-40%) and CPU even when idling overnight. Is this normal? I was expecting it to be close to 0% when idling. How do I figure out what's causing the CPU utilization?