Are there any requirements for a computer when it comes to being compatible with a graphics card or can i just use my old computer and a graphics card which is much newer (if i bought a good enough PSU)?
It also needs to be "compatible" with your CPU. I was just in a thread where someone wanted to spend $200 to get a GPU. He was still using an old P4 CPU however. He wouldn't get the frame rates he was thinking he'd get if he used such a slow CPU.