im curious if its possible to somehow manage the power consumption of our phones during heavy gpu usage. when i watch youtube or play games it drains super quick. i was just wondering if there was a way to make it work more efficiently with our processor or is the processor clocking what defines the gpu power consumption?
th3_g00b said:
im curious if its possible to somehow manage the power consumption of our phones during heavy gpu usage. when i watch youtube or play games it drains super quick. i was just wondering if there was a way to make it work more efficiently with our processor or is the processor clocking what defines the gpu power consumption?
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The Qualcomm MSM8655 is what's known as a SoC, system on chip. The GPU is on the die. Whatever demands are made on the GPU are effectively made to the whole chip. If you're looking to reduce the power it uses, you need to being down the top clock rate.
I would like to know if it is safe to change the max cpu lock from quad core to single core mode when in need of battery or even other modes? How about for daily use but still needed battery life?
BelJanss said:
I would like to know if it is safe to change the max cpu lock from quad core to single core mode when in need of battery or even other modes? How about for daily use but still needed battery life?
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you can find more information about this in Siyah's Kernel thread.
I locked mine to 2 cores. After researching about turning off cores, it's mentioned that it's best to just leave all 4 cores on and let android manage the power. I will turn all 4 cores on later because i'm testing dual core mode for personal reference but it maybe void because i've under volted my cpu along with turning off the 2 cores. So far my battery is draining less and i'm using my phone more this morning. I don't even notice a performance drop. My phone is still smooth..but then again i do not use my phone to play games that require a lot of performance.
Thanks for your response. I'm now testing my s3 in a single core mode and battery draining is less also. For the performance I can say that it is not bad. However, what I'm afraid of it is if has bad effect on the cpu itself.
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!
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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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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 !!!
If I set the Max CPU clock speed of my screen off profile to be the same as my mininum CPU speed (378 Mhz), will this really save my battery when my phone is idle with screen off?
The only thing that really runs in the background on my phone are the occassional Gmail and Dropbox photo syncs. One on hand, by allowing my phone to use the full range of clock speed, it can complete the necessary tasks faster and go back to deep sleep faster. But on the other, by restricting the clock speed to a low speed, it's using less battery while running but for a longer time.
Which scenario is best for saving battery?
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.