laptop cpu usage question

[ciproxr]

noticed on my laptop that when plugged in vlc uses 16% of my cpu to watch a movie but when i unplugg my laptop vlc uses 32% of my cpu to watch the same movie.

why does vlc need more cpu to do the same thing when plugged in ?

makes no sense to me

 

[Fraggable]

Because your CPU clocks back when working on battery...

 

[Ruptga]

Originally posted by: Fraggable
Because your CPU clocks back when working on battery...

That's my guess too. Santa Rosa laptops vary their FSB from 800 to 400 when saving power, which necessarily halves the CPU's speed as well, so it makes sense your usage would exactly double. Even if you've got an older laptop, they all throttle, my T2300 goes from 1.66Ghz to 1Ghz, which isn't half, but you get the idea.