CPU Frequency control

[Urza9814]

So I'm trying to figure out how to get the most out of my laptop battery. So far I can get just over 4 hours, but I'm looking to see just how high I can go on my cheap, low-capacity battery. The thing I'm having trouble with is managing the CPU. Currently, I use KPowerSave, which I believe uses cpufrequtils to set the "P States". But the problem is, my only choices are 'Performance', 'Dynamic' and 'Powersave'. On Vista (ugh, I know) I believe (haven't used it in a loong time, for obvious reasons) I can set exactly what frequency to set them at, and even shut down one core entirely if I want. Is there any way to do such a thing in Linux? Because the best I can get so far is both cores running at 800MHz, which is good, but there are times when all I'm running is IceWM and CoolEdit, so I could surely survive on much less. Any suggestions?

[demonseth17]

So I'm trying to figure out how to get the most out of my laptop battery. So far I can get just over 4 hours, but I'm looking to see just how high I can go on my cheap, low-capacity battery. The thing I'm having trouble with is managing the CPU. Currently, I use KPowerSave, which I believe uses cpufrequtils to set the "P States". But the problem is, my only choices are 'Performance', 'Dynamic' and 'Powersave'. On Vista (ugh, I know) I believe (haven't used it in a loong time, for obvious reasons) I can set exactly what frequency to set them at, and even shut down one core entirely if I want. Is there any way to do such a thing in Linux? Because the best I can get so far is both cores running at 800MHz, which is good, but there are times when all I'm running is IceWM and CoolEdit, so I could surely survive on much less. Any suggestions?

well I did some reaserch (I know it doesn't seem that way ;) but I usually do that when urpmi code doesn't work cuz I don't know the program or daemon name) if you're using mandriva free 2009.0 you will find in rpmdrake a daemon and a program that could work for you (seriously I haven't try it cuz I don't need less than 800 MHz)....so hopefully it will work for you :) see my screenshot and if you haven't add easy-urpmi reposit..do it first :)

[Urza9814]

Huh. thanks. I'm on 2008.1 actually, but it's in my urpmi database as well. Unfortunately, urpmi appears to have _locked up_ trying to install it (I have _never_ seen that happen before...maybe it's just taking forever to install, though I doubt that), but we'll see. I'll get it installed eventually. lol

 

edit:

Ah, there we go. It doesn't let me specify a CPU speed manually, but it does let me disable one. I've got my battery life up to 4:30 now :) lol

Edited March 25, 2009 by Urza9814

[daniewicz]

Have a look at powertop if you are interested in increasing your battery life further:

 

http://www.lesswatts.org/projects/powertop/

[Urza9814]

Ah! I like that powertop program. The only problem I have is it's suggesting things like 'Enable SATA ALPM link power management' and 'changing VM dirty writeback from 4.99 to 15'. I have no idea what those mean, and I'm not sure I want to be changing things I don't understand...because I don't know how they'll impact performance when I'm _not_ trying to squeeze every last minute out of my battery.