Can the iMac graphics cards run these games?

Hey Everyone,

I am looking to buy a new Imac 27", the only question i have is about the video card..

4670 vs 4870, i want to be able to bootcamp and play COD modern warfare 2 and a few other games and retire my AMD 3x computer so I have more room as my G5 is already hogging alot.

I tried to find out if the cards can run them and it looks like it will just wondering if anyone has ran new games and how well they worked.

My thought is buy the 27 inch, add the g5 through the adapter and then I can reclaim some of my deskspace...

I run COD:4 on my mac that I bought last year (mac version) decently and Sauerbraten (highest quality settings) just fine with some lag on multi-player with 64 player games on large maps.