Hello experts, My PC is of following specs, Pentium E5200 Dual Core 2.5GHz 350W PSU 2GB DDR2 Ram 17" LCD, I had bought an 8400gs 1024mb ddr3 graphic unit. But it is awful. My pc restarts when it overheats. So I have decided to update to a better unit. My needs are to play games like Crysis 2, Dirt 3, GTA 4 etc in good quality. Can anyone help me to decide a good graphic card. Which one is better? ATI or Nvidia? My budget is 4000. Please help me experts. If u cn help in the case of 8400gs, its most welcome.