Strange thing here. Is ME just that crappy that it uses alot more CPU cycles than XP, or is something just weird? I'm using ASUS Probe on a A7V266. Very strange...
Install Rain or CPUIdle in ME, and come back with temps. I think you will find the temps extremely similar. Look at the Task Manager in XP - System Idle Process should be using much of your processor. That is what keeps the temps down. Read the information on Rain or CPUIdle and you will see how these things work, and then you will understand System Idle Process in 2k and XP.
Actually SETI@Home is taking all of my CPU cycles (in ME and XP), but I've noticed System Idle Process does take over the majority of my cycles when SH isn't running.
I'll get CPUIdle some other time, and post back, I'm off to work now...