Opteron 170 @ 2.5ghz
SI-120 w/ 5000RPM 120mm Deltafan, it rocks
30-36 idle, dependant on ambient temp
40-46 load, dependant on the application
Ive got the fan running at a max of 55%. 2500RPM, so it can be cooler, but then it would also be noisey, its set up just right for me.