I have a Q9550 running at 3.5Ghz (412X8.5) under 100% CPU load and temps right now are core 1 @ 60C, core 2 @ 54C, core 3 @ 52C, and core 4 @ 52C.
Idle temps are core 1 @ 47C, core 2 @ 42C, core 3 @ 42C, and core 4 @ 42C.
These readings are RealTemp core temperatures and the room is at 20C.
Cooling solution is an OCZ Vendetta 2 with one 120mm fan and three 120mm case fans.
GPU is also under full load.
CPU voltage is at 1.31V
Hope this helps.