I have a PNYGTX560Ti in my working rig, with the following settings at stock: GPU Clock 850Mhz, Gpu Voltage 987mV and Memory Clocl of 4200Mhz. When I run Unigine Heaven Benchmark it gets pretty hot, 75C. But I use only autocad and 3DSMax, and working on both of the programs with ASUS GPU Tweak open I never see more than 40C, so I overclock it to 1020Mhz (1012mV) and 4300Mhz on the memory, working I never saw it reaching more than 42C, but it crashes when I tried to run Unigine, I am not going to game on this rig, but it is safe to tun at this clocks? Or you guys recommend increasing the voltage?