Found a great Graphics Card Calculator

Cool tool. Nice to choose the specific cards you wanna compare. Specially chosing the one you already have, and the one you are planning to buy.
Not always you`ll find that in reviews.

But, when comparing my old card (8800GTS 512MB) to the newest ones (GTX470/480 etc), it almost looks like the 8800 isnt even able to play Call of Duty1. Which is not true at all, of course  

Only looking at numbers and graphs wont tell the whole truth about the card.

But a nice tool if you know what to look for in numbers like that.