I doubt that very much, or we wouldn't have variable speed fans. I've monitored CPU temperature when doing compilations; it goes up significantly. That suggests that the CPU is drawing more power at such times.
I don't doubt what you are saying. However, I did say, "in the grand scheme of things", meaning that the heat given off by the CPU, and change thereof, relative to the constant heat given off by the rotation of hard drives, the heat given off by the power supplies, etc., is still small.
Of course, there's another implication -- if the CPU isn't using the power, the draw from the power line is less, which means that much less electricity is being used.
An important point, but I still bet relatively small. It's going to be a busy weekend at the Rubenstein Lab (aka, my garage) this weekend; I'll post results to my findings. -- Alex Rubenstein, AR97, K2AHR, alex@nac.net, latency, Al Reuben -- -- Net Access Corporation, 800-NET-ME-36, http://www.nac.net --