Originally posted by beedubaya
I agree with the guys above. For one thing, you don't have good cooling and ventilation in a Shuttle system. They aren't meant for power gaming PCs, but more for saving space. The X800 series runs hotter than about any series of cards out right now. My X800 Pro gets 80*C on a regular basis, and I have 7 fans cooling my case.
Secondly, shuttles use micro ATX motherboards, and Micro ATX power supplies don't put out the power that you need for an X800XT.
80C!!!! What? Dude, you need to visit the Arctic-cooling.com website and buy yourself an ATI Silencer. I've got a RIG with a X800XT PE it's OC'd to 560/600 and I have a ATI Silencer 4 with AS5 on core and all 8 rams. The hottest i've ever monitored my GPU @ during hours of gameplay was 58C. Idle it's cool between 38-42C. Mostly load temps are 50-55C.
Your GPU is running way too hot. Wipe out a fryin' pan a dozen eggs, i'll bring the O.J and the bacon!!!