Its not drivers, software or anything relating to a bug. Your CPU is causing the GPU to bottleneck unfortunately. If your buying new I wouldn't even consider LGA775 platforms now. Not all LGA775 CPU's will probably be compatible, and since the CPU is already light years old, it would be wise to update. You need to be looking at a minimum of AMD3, or LGA1156/1366 (i3/5/7 or the newer SandyBridge LGA1155. For the same money your GTX570 cost you could get a 6 core AMD Phenom 1055T/1075T, and a motherboard, and 4/8GB RAM. A new Intel SandyBridge setup should be possible for around that price as well.