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seanmcken is offline seanmcken
2012-11-26 , 06:36
Posts: 863 | Thanked: 213 times | Joined on Feb 2012 @ Goa
#1
so as i named this thread i want to know something about this phone (n900) and other phones. when i overclock the n900 to 950 or 1100 the battery of phone sucks like a thirsty guy drinking water and other phones with 1 ghz or more than that gives good battery life so wat's exactly reason behind this? i know this question is useless but plz let me know.
 
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pichlo is offline pichlo
2012-11-26 , 07:39
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#2
As a rule of thumb, power consumption of modern electronic devices increases with the square of the frequency. That is, if the frequency increases 2x, power consumption increases 4x. Frequency 10x, power 100x, etc. The reasons are several and, from the way you ask the question I suspect they may be a bit too technical for you, but simply put, tiny components within the chips draw tiny jolts of current on every status change. The overall power consumption is a sum of these tiny jolts. Of course, with an increased frequency you have more of these status changes per any given amount of time.

There is a flip side. With an increased frequency, a CPU can finish any given task quicker and go to sleep sooner, so a small increase of the CPU frequency can actually reduce the power consumption. It is generally agreed on this forum that the optimum frequency for the N900 is 800 MHz (someone please correct me if I'm wrong). However beyond a certain point, the power increase caused by an increased frequency outweighs the positive effect of more sleep and the battery drag goes up.
 

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reinob is offline reinob
2012-11-26 , 08:20
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#3
Originally Posted by seanmcken View Post
when i overclock the n900 to 950 or 1100
Do you LOCK the frequency to that value, or do you RAISE the maximum to that value?

Locking the frequency (even @600Mhz) will result in worse battery life than leaving the kernel to manage the frequency (even if you raise the maximum to 950Mhz).

the battery of phone sucks like a thirsty guy drinking water and other phones with 1 ghz or more than that gives good battery life so wat's exactly reason behind this?
Other phones tend to force-sleep when the user is not actively doing anything (i.e. screen off -> processor off). This is not the case with the N900. Try to actively use (keep screen on) one of those 1Ghz-processor phones and you will see how the battery drops. I've seen a colleague's Samsung S3 drain from 100% to 20% in 4 hours, with very little use. I charge my N900 every 3 days.
 

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freemangordon is offline freemangordon
2012-11-26 , 08:24
Posts: 3,074 | Thanked: 12,964 times | Joined on Mar 2010 @ Sofia,Bulgaria
#4
Originally Posted by pichlo View Post
As a rule of thumb, power consumption of modern electronic devices increases with the square of the frequency. That is, if the frequency increases 2x, power consumption increases 4x. Frequency 10x, power 100x, etc. The reasons are several and, from the way you ask the question I suspect they may be a bit too technical for you, but simply put, tiny components within the chips draw tiny jolts of current on every status change. The overall power consumption is a sum of these tiny jolts. Of course, with an increased frequency you have more of these status changes per any given amount of time.

There is a flip side. With an increased frequency, a CPU can finish any given task quicker and go to sleep sooner, so a small increase of the CPU frequency can actually reduce the power consumption. It is generally agreed on this forum that the optimum frequency for the N900 is 800 MHz (someone please correct me if I'm wrong). However beyond a certain point, the power increase caused by an increased frequency outweighs the positive effect of more sleep and the battery drag goes up.
The "sweet spot" for n900 is 500 MHz and anything above 600 MHz shortens battery life a lot.
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seanmcken is offline seanmcken
2012-11-26 , 08:50
Posts: 863 | Thanked: 213 times | Joined on Feb 2012 @ Goa
#5
Ok guys thank you very much to answer this useless question
 
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