why is there a huge difference with working on battery... ??

[masterus]

hi,

could anyone please explain me why there is so huge difference with working on battery between Ubuntu and WinXP-Pro
it looks like WinXP is few levels above Ubuntu on that field
on WinXP have about 1,5h working time , on Ubuntu have 1h working time
yes , I know have the old battery but inspite of that 30min difference is huge
would be very gratefull for all answers and tips how to change that issue

thx&rgds,

[aaa]

Are you using the ATI drivers with PowerPlay? There should be a Catalyst Control Center for ATI under Linux too.

[Marin85]

Besides, effective power management under Linux is not as simple as in XP. In XP you can set it all using Lenovo Power Manager, but in Linux you will have to "tweak" a little more to achieve the same results (or even better )...

[Superego]

effective power management under Linux is not as simple as in XP.

Exactly. I get roughly the same battery life, but it requires me to use a combination of things....cpu frequency scaling, Powertop, and local scripts to tweak my hard disk. The other benefit is that now I know a little more about my system and how to control it .

[Marin85]

I dream that someone would write an utility to get all these tweaks and functions in one place...

[TheRedFox]

I know! it's crazy! with Windows XP my battery life varies between 3.5h (with minimal tweaking, i.e. processor on dynamic switching, gfx card underclocked) to a bit over 5h (with maximum tweaking, screen at lowest brightness, wireless off, processor @600mhz gfx underclocked, etc.). in Arch Linux (which is mostly faster) it ranges between 2.5 hours or so with no tweaking, to 3.5h with processor @600mhz, gfx @90mhz, screen at lowest brightness, etc. maybe as much as 4h if wireless is off. it is slightly worrisome. if I ever figure out how to fully tweak my X31, I'll try to make a python or shell script to automate the process.

[aaa]

With the X31 and others with ATI 7xxx cards you just can't match XP, the drivers do not have proper PowerPlay support. Your GPU at 90mhz still has the voltage on full blast, which is what matters most.

Undervolting the cpu will help with both OS's btw.

[TheRedFox]

makes sense. I plan on recompiling my kernel with linux-PHC eventually so that I can undervolt.