Looking at apple's tests (which may or may not be 100% accurate), they claim quake4 runs 5.1 X faster on the top end with 4870 vs the octo 3.2 with 2600 of last gen. On barefeats.com if you compare their old tests of the 3.2 with 2600 http://www.barefeats.com/harper8.html Quake4 gets: 32 FPS in the test on 2600 84 FPS on the 8800GT and.... 163.2 FPS on the 4870 with the new system if their test is correct. That's a pretty significant improvement. Literally twice as fast as the 8800. How much of that would be the card and how much would be the system/CPU? If barefeats was working right now, I could check how the 8800 compared to the 4870 on windows, but I don't think it was 2X.