I am running a 300a@504 on a Asus P2B. It is very solid as long as I don't run a 3d game. It will run for a while then it just locks the system. I am only at 2.0v but I'm not sure if is the CPU or the video card (viper V770). I have a peltier cooler on the cpu and I added a fan to the heatsink on the v770. Any suggestions?