I have been following Galaxsih kernel thread and there was a discussion whether undervolt saves battery or not.
Some people believe it does not save battery life.
Originally Posted by bedalus
Miscellaneous
[Q] You claim you cannot increase battery life using UV beyond 2%. Justify yourself!
[A] When the processor is in use (i.e. not asleep or idle) UV does save a tiny amount of power. I tested with the most extreme UV my phone could handle. With a high performance governor, e.g. smartassv2, extreme UV would reduce CPU drain by 13%, or about 7 mA. With a governor that keeps the CPU frequency low, CPU drain would be reduced by about 18%, or 4.6 mA (weighted - see the spreadsheet starting cell H88).
Remember, these savings are limited to the processor, and only when it is active. For most users, this will mean the screen is on. For comparison, the screen on minimum brightness displaying black uses 9mA. On max brightness, displaying white, it uses 690mA. Let us assume some median value, ~350 mA.
A saving of 4.6 mA out of at least 350 mA (screen) plus 20 mA (CPU)
= 1.2%
A saving of 7 mA out of at least 350 mA (screen) plus 50 mA (CPU)
= 1.8%
So, regardless of your choice of governor, even with extreme undervolting, you are not going to be able to increase your battery life by more than 2%.
But eric-filth and some other people including my self claim that it saves battery.
i have tested it as eric suggested (run antutu 10 times with and without UV from 100% battery.)
without undervolt i have lost 10% whereas with UV i only lost 6%
so people please share your experiences with UV.
Do you think it helps in terms of saving battery?
Some people believe it does not save battery life.
Originally Posted by bedalus
Miscellaneous
[Q] You claim you cannot increase battery life using UV beyond 2%. Justify yourself!
[A] When the processor is in use (i.e. not asleep or idle) UV does save a tiny amount of power. I tested with the most extreme UV my phone could handle. With a high performance governor, e.g. smartassv2, extreme UV would reduce CPU drain by 13%, or about 7 mA. With a governor that keeps the CPU frequency low, CPU drain would be reduced by about 18%, or 4.6 mA (weighted - see the spreadsheet starting cell H88).
Remember, these savings are limited to the processor, and only when it is active. For most users, this will mean the screen is on. For comparison, the screen on minimum brightness displaying black uses 9mA. On max brightness, displaying white, it uses 690mA. Let us assume some median value, ~350 mA.
A saving of 4.6 mA out of at least 350 mA (screen) plus 20 mA (CPU)
= 1.2%
A saving of 7 mA out of at least 350 mA (screen) plus 50 mA (CPU)
= 1.8%
So, regardless of your choice of governor, even with extreme undervolting, you are not going to be able to increase your battery life by more than 2%.
But eric-filth and some other people including my self claim that it saves battery.
i have tested it as eric suggested (run antutu 10 times with and without UV from 100% battery.)
without undervolt i have lost 10% whereas with UV i only lost 6%
so people please share your experiences with UV.
Do you think it helps in terms of saving battery?