For few days I will not have access charging my battery. I am thinking about disabling cores and lowering maximum cpu frequency for better battery life. I have root and carbon rom. Is it efficient disabling cores and make one core at %100, or 4 cores at lower use percentage? And what are my other options to save battery? I don't care much performance. I don't mind slowing down. I wish I could test myself but I don't have time to test.
Daily I use 3 cores at 1036MHz without excessive lags. I'm using SetCPU to do it. It's possible to create profiles and set frequency, governor and scheduler when a specific app is launched, when battery reaches into a low level, when screen is On/Off, etc.
Screen time about 7,5 hours.
For gaming I need to change it, of course.
I'm using Abricot kernel.
Related
I was just wondering what people get for battery life with miui 1.7.8 and OTB .13 kernel.
Also, what does overclock actually mean? Does it mean that setting the min and max to 1400Mhz in Voltage Control or remain the min to 100 and max to 1400Mhz?
I'm currently on noop, ondemand and min=100Mhz, max=1400Mhz with nothing UV'ed.
Please help me to get better battery life!!!!!!!!
Your CPU by default can do, unmodified, a certain number of commands per second. These commands are measured in Hertz, thus a 1GHz processor does about 1 billionish commands per second. Overclocking means you allow your processor to do more commands in the same time frame. The downside to this, however, is that more electricity is flowing through the CPU, thus draining the battery more. Having a lower clock speed will save some battery life.
That being said, I have kept my CPU clocked at maximum of 1GHz, with the I/O Scheduler set to deadline and the CPU Governor set to smartass, and I'm getting about a day out of my battery, maybe a little less. I have no idea if that's the "optimal" battery saver setting, but it works for me.
I do have a question, though... What do those two settings mean, anyway?
1n73rn37_j3d1 said:
Your CPU by default can do, unmodified, a certain number of commands per second. These commands are measured in Hertz, thus a 1GHz processor does about 1 billionish commands per second. Overclocking means you allow your processor to do more commands in the same time frame. The downside to this, however, is that more electricity is flowing through the CPU, thus draining the battery more. Having a lower clock speed will save some battery life.
That being said, I have kept my CPU clocked at maximum of 1GHz, with the I/O Scheduler set to deadline and the CPU Governor set to smartass, and I'm getting about a day out of my battery, maybe a little less. I have no idea if that's the "optimal" battery saver setting, but it works for me.
I do have a question, though... What do those two settings mean, anyway?
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Click to collapse
What do you mean by two settings?
Like, what are I/O Schedulers and CPU Governors? That last question was me hijacking the thread.
I've install Rom Toolbox,
and i saw there is a "CPU slider" where i control the clock speed.
i've put it to 1000MHz instead of 1200MHz and tested it for several days
i really dont feel any difference in performance.
browsing seems same, games like asphalt is equally smooth.
heating is similar, equally warm.
the only difference is quadrant benchmark.
1200MHz scores 3200-3400
1000MHz scores 2600-2900
frankly speaking, i'm not sure if there's any difference in battery life.
is there any way to accurately test whether the clock speed affects the battery life?
i've seen other threads, where there are very different opinions.
some say it will improve battery life, and some say its worst.
http://forum.xda-developers.com/showthread.php?t=726019
Quote: (SetCPU doesn't make a difference in battery life, it can only shorten it. The kernal already has the best settings for CPU speed built in.)
http://forum.xda-developers.com/showthread.php?t=1305465
Quote: (if you are able to stand the side effects of underclocking, it will surely boost your batery life.)
On my SGS2 program called CpuSpy shows that 1200MHz is about 1% of total cpu time (remember that governor is ondemand and CPU is at 1200 only when need it). If power consumption is directly proportional to clock speed by limiting it to 1000MHz you will get about 20% less power usage by 1% of time... looks like 0.2% power saved ? Soo if Your phone works for about 48h on one charging this way You can get about 6 extra minutes. It's just my guess...
Also have to consider if slower cpu causes screen to eat power for longer time... (because You have to wait longer for operation to complete)
slig said:
On my SGS2 program called CpuSpy shows that 1200MHz is about 1% of total cpu time (remember that governor is ondemand and CPU is at 1200 only when need it).
If power consumption is directly proportional to clock speed by limiting it to 1000MHz you will get about 20% less power usage by 1% of time... looks like 0.2% power saved ? Soo if Your phone works for about 48h on one charging this way You can get about 6 extra minutes. It's just my guess...
Also have to consider if slower cpu causes screen to eat power for longer time... (because You have to wait longer for operation to complete)
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HI, thanks for replying. I understand what you mean. the phone dont operate at 1200MHz all the time. but when using browser, and playing games, such as asphalt, it runs at max CPU usage almost the entire gaming duration.
Anyway.....
the real question is whether the clock speed is directly proportional to the battery consumption.
while reading your post, i thought of a brilliant ideal how to verify this.
the CPU slider not only allows you to set the max CPU speed,
you can set the min CPU speed as well.
So, i thought of an experiment, lets set the min & max CPU to 1200MHz,
this way, the phone will be running constantly at max CPU even when its idle.
let the phone be turn on till it run out of battery, record the time, T1.
then repeat again with max and min CPU set to 1000MHz.
record the time it is turn on till it run out of battery, record time as T2,
then compare T1 & T2, this could certainly work.
it would be nice if any member here happens to have 2 sgs2, and tried them ;-)
There are two more things to consider
1. CPU is not the only element that consumes power.
2. SGS2's Exynos is always clocked at 200MHz when the screen is off - check if this minimum slider affects that too.
Please let know how your experiment goes.
Regards
when the screen is off, the phone will be in "deep sleep" state. i think thats less than 200MHz.
anyway, i wont be doin this experiment any time soon.
you see, this is my only phone, i need to use it.
i dont have much oportunity to leave it and wait for it to run out of juice.
still, i'll try it when i have the chance.
First of all, we are talking about Stock ROM governors. Of course we could discuss other kernels here, but keep in mind that this, mainly, a comparison of Performance vs Ondemand governor for battery savings.
Someday i've read here in those threads of Governor Descriptions a theory that Performance Governor could save Battery against OnDemand and even others governors, because he does not waste energy and time trying to scale, since it scales to full clock, and with that it could finish its tasks quickier than others, allowing it to return faster to iddle.
So, after reading that, i felt tempted to ride this horse
I've installed setCPU and created a profile in the first one for Screen Turn Off, setting a low max frequency (around 500mhz), and with the help CPU Sleeper (Turn of one of the cores when screen is shut down), i could maximize this economy. I guess the only demanding processes my Xperia S could run when Screen Off are, of course, music playing apps.
Result: A smooooooth UI and it seems the battery comsumption is a bit better (maybe more than a bit) than OnDemand. I don't have concrete numbers, but with the help of GSam Monitor and a Use with some moments of Intense WhatsApp, some mild WhatsApp, a bit of UI browsing, App Uninstalling and about 20% brightness i calculate that i would have a Battery Life of about 20 hours!
My next step is to start to set a different Maximum Clock per App (setCPU 3.0 allow me to change governor and clock based on active app), lowing it enough so that i have a smooth app operation and battery economy.
What do you think guys?
Hey guys,
I did an experiment not a long time ago. I have my old phone with 4.1.2 Android and I went on a trip for a few days. Typically my phone discharges after 12-15 hours even without using anything (old battery) with smartassv2 or just conservative mode. Before going on the trip, I've set the minimum clock to the lowest possible and set the mode to powersaving (always using the minimum). And after 3 days the battery still was at 86%.
So what's the problem with the Android OS itself? Or have I just gotten some magical experience? Why does it use such a large clock rate for the processor when it's locked and using any preference script apart from power saver?
Thanks a bunch!
First of all, battery life depends on your battery type and capacity.
Second of all, when you underclock your cpu to the minimum frequency, battery consumption will decrease a LOT but using this frequency for apps use is practically impossible.Also, display causes less battery life.
Hope i helped !
Forgot about this topic. Yes, mate, I understand that, but the minimum frequency is enough when I don't have any apps running in the background. Seems like android still has a lot of power managment programming to be done under standby.
Maybe I wasn't clear enough, but if you just use any governor (with minimal frequency set at the lowest) apart from "powersaving", it will use more power on standby, then powersaving with the minimal frequency set.
Hi Guys,
I am a noob here. I have never used a android phone before, not even a iPhone - so basically no smart phones.My first smart/android phone would be Nexus 4 which would be coming tomorrow.
I have been reading threads to understand andriod architecture and believe have understood to certain extent.
I have a question in clocking the CPUs and Voting.
As I understand, we have 3 states -Max, Min and Sleep for a single CPU core
Max - The frequency (clock speed) which CPU executes or maximum speed which CPU sends signals to its components and get the response back. This would be used when the system is on - which means when user is doing some process.. like texting, video chat, gaming (this case GPU is also involved) etc.
Min - This would be for background process when the user/phone is idle - that when screen is off (eq - gmail sync, facebook sync etc..)
Sleep - Screen off and no background process , the core will be in sleep.
And the battery level will be directly propotional to speed of CPU with respect to the volting.
Now lets say there is a single core processor in a phone which can clock upto 1.5GZ. and the stock kernel comes up with Max - 1.3GZ and MIN -0.5 GHZ.
Question is abt overclocking minimum frequency
1. why not overclock the Mn frequency to 1.3Ghz? because the backgroundprocess would be fast and phone/core will be sleeping after that,
which means process consumes more battery at that particular time but overall baterry should be efficient as there would be more sleeping time.
2. About volting, so far I have not seen min and max volting. So is there only one voltage/power drawn for max and min CPU speeds by CPU?
Please correct me if any of my statements is wrong.
Appreciate your help,
Thanks,
Franklin B.
Overclocking the minimum frequency to 1.3ghz would probably decrease your processor's life if you use your phone too much but I have been actually increasing my phone even 200mhz more than it was in stock ROMs, i've been using my device for more than 2 years and it still works perfectly. Finally, it all depends on how much your phone is good.
I also decreased the cpu min and max frequency when phone sleeps to 256 mhz which decreased a lot battery consumption.
Hope i helped !
Don't forget the THANKS button
1.you can but your battery life will be drastically reduced! There is a good amount of time after the screen is off and before the phone sleeps! So if over clock the min to 1.3Ghz, the processor will be running at 1.3Ghz till it goes to sleep! But if that's what you want you can do that!
2 . I'm not so sure about this topic either but I think the processor operates at a particular voltage and I could be wrong!
Sent from my GT-P3100 using Tapatalk 2
Thank you Guys
Franklin Bernard said:
1. why not overclock the Mn frequency to 1.3Ghz? because the backgroundprocess would be fast and phone/core will be sleeping after that,
which means process consumes more battery at that particular time but overall baterry should be efficient as there would be more sleeping time.
2. About volting, so far I have not seen min and max volting. So is there only one voltage/power drawn for max and min CPU speeds by CPU?
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Click to collapse
Hi, I received your PM. I agree with the guys about the heat issues, longevity, and battery life etc. The answer to your question #2 will help you better understand things.
In all kernels, there are frequency/voltage scaling tables. For every frequency step (clock speed) in the table, it corresponds to a specific voltage. It gets a bit more complicated than this of course, but that is the basic way things are setup in the kernel. The higher the frequency, the higher the voltage is required to be to keep the CPU (or GPU, bus, RAM etc.) stable at a given clock speed. The more voltage, the more current, and the more heat is generated. The longer you stay at higher clock speeds/voltages, the better the cooling system you need to have. Supply regulators are defined to feed the core and rail voltages so that the processor can live in a happy environment no matter what it is being asked to.
As far as power consumption, it's all about getting a unit of work done in a timely/efficient fashion using the least amount of power consumption. If the phone is sleeping, the word "timely" takes on a different meaning so then it is mostly concerned with power consumption and getting the background tasks completed effectively without having the phone experience the sleep of death (SOD). What you are talking about is the theory of "race to sleep" so that the work can be done quickly and the phone can go back to sleep where it uses the least amount of power (clocks actually turn off during deep sleep and cores are turned off). However, there is a happy medium to this theory and heat and battery consumption are the main enemies. Heat can also rob efficiency, more current is required when a circuit heats up. The more a phone wakes up to do syncs for email, apps, social networking, missed calls etc., that work can stack up throughout the day. The question comes down to how can the device get this work done using the least power and keep the device cool. On the N4, the lowest frequencies can use ~700-800mV per core while the highest frequencies can use ~1100mV. There is a drastic difference in the amount of heat generation between this range.
I think this should give you the general idea and maybe more that you wanted to know! Here are some links to check out if you are interested. Google and you will find many many more articles and research papers.
http://en.wikipedia.org/wiki/Voltage_and_frequency_scaling
http://atrak.usc.edu/~massoud/Talks/Pedram-dvfs-Taiwan05.pdf
Thanks a ton !!!