Hey I'm only familiar with Nvidia GeForce cards and I know next to nothing about ATI so I was wondering if there's some sort of chart or generator which demonstrates the Nvidia equivalent of each ATI card and vice versa? There's some shiny rep waiting for the most helpful answer :P
Here you go. Just click the model graphics cards you want to compare and test you want to compare them with and it will give you detailed info on FPS etc. Theres a pile of tests just pick the one's you want to look at. If your looking a performance vs price just newegg the card your interested in and see what the price difference's are.