I'm playing with a Asus P5WD2 P and a 640. Right now I'm at 4ghz (16x250 - default voltages) and temps seemed a little low at just under 50c while Priming Blend. Then I started two instances of Prime (Large and Small) and it shot up to 58C and stayed there. This is with a Thermaltake BT. I normally OC AMDs so I don't have a reference point to work with since this is the first Prescott I've gotten my hands on. Unless someone tells me otherwise I'll assume thats a normal temp range.

BTW - This is not my rig so I can't take any chances with and won't move off default voltages. But I am curious what the max safe temp would be on this CPU?