Battery savings.

[ethoxyethaan]

normally (windows xp) my battery lasts for over 4 hours if i turn my screen on low brightness.

but ever since i fully switched to Ubuntu i get a miserable 1- 1.5 hours.

i read some things about:
hdparm
Dynamic Tick
and this site:
http://www.lesswatts.org/projects/powertop/

but it didn't make me any wizer on the subject.

so, is there any guide on here so i can get my 4 hours of battery life back :(. (i did look around but maybe you can recommend the best option)

Dell latitude d830 Ubuntu 7.10.
average ram use: 200
cpu: idl (slideshows or Pdf files)

[wannadumpwindows]

I must be lucky. I bought a new computer with Vista pre-installed. With Vista I get about 55 minutes, even on the power-saver setting with the brightness all the way down and the volume off. With Ubuntu I get about double, even when I'm running it full bore. I just don't understand how there can be such a huge difference either.

[twright]

8.04 has quite a few new power saving features, i find that my battery usually lasts longer in ubuntu

powertop is used for 8.04, it basically allows people to see how to make their programs use less power

enabling laptop mode also might help