Power consumption Linux vs. Windows
Hi! I found Phoronix when I bought a used HP NC8430 laptop that was my first laptop with a dedicated GPU, Mobility Radeon X1600. Unfortunately it was around the time the GPU was deemed as "legacy" and left without proper power management. Soon I got fed up with cooking my laptop and settled with good and steady Debian Lenny whose Catalyst version still supports my chip. A few weeks ago I got interested in the power management advances and to my delight the newest kernel is doing a good job in keeping the temperature of the GPU down.
However, this is not reflected in the power consumption. To be honest, during the times my laptop was cooking, I didn't even measure the consumption, but now that everything should be more or less ok, I'm still getting almost double power consumption (22-27 W in Linux vs. 13-14 W in Windows Vista). I keep reading that Windows power management is better, the dedicated device drivers are available only to Windows etc.
However, I'm unable to understand the difference. I'm not a programmer, but let's say I "turn off" all my unnecessary devices like serial ports, cd-rom, USB etc. If I'm running only the core devices, shouldn't the power consumption be minimized? When I have time, I am going to experiment compiling my kernel with the minimal amount of devices to see if it has any effect. But if someone already has done this, or has the knowledge to answer, please reply.
The funniest thing is that in Windows Vista to get 13-14 W I have Aero running, changing to "classic" theme actually increases the consumption. I haven't succeeded in lowering the consumption by tweaking, only making sure that the processor is not in performance mode and GPU is in battery saving mode is enough. With linux I am doing all the possible tweaks plus what Powertop says, and still get over 20 W.
My mission is not accomplished (and I can't get rid of Windows) until I get linux at the same level. Until then, I only have a Desktop linux, but a Windows laptop.
Needless to say, I welcome all benchmarks related to power consumption. And I hope to read some good advice from the expert tweakers here :)