I came across this utility today when I was looking for a way to shut-up my PC fan (I know they are kinda unrelated – but who knows what you can find in forums!). Just in case you haven’t read the title of this blog, it’s called SpeedswitchXP (http://www.diefer.de/speedswitchxp/) and it basically allows you to dynamically adjust your laptop’s CPU clock speed – like Intel’s SpeedStep for pre-XP machines.
I know XP sort of automatically does the switching of clock speed but unfortunately, there’s no way of adjusting when it does that – so the probable net result is more battery consumption, as XP does not adapt the clock speed quickly enough.
Anyway, I gave that utility a spin just now and so far, I noticed my laptop runs a hell lot cooler but I haven’t yet had time to test whether that makes a big improvement on battery life (but I suspect it will).
So yeh, laptop owners, if you want to squeeze more battery life out of your laptop, give this application a spin.