Ciao Same issue here: after 2 minutes or less of high gpu load (Crysis or 3D Mark) I got no monitor input, sound loop, reboot... Tried with a fresh reinstall of Windows Xp and now Vista 64 bit, nothing changes. Tried installing last motherboard firmware, same story. I'm using stock frequencies (never overclocked), my case is well-ventilated and my psu is powerful. Gpu temperature is not the problem, to proof that I got some stats with rivatuner: As you can see temperatures never rises over 51°C and when the system crashed the values gone out of bounds. I'm still searching for a solution.. I'll try down-clocking the gpu.. Nobody found a solution till now?