Unreal Tournament 2004
Unreal Tournament 2004 is the latest game in the UT series, adding vehicles, new game types, and new maps to the very popular UT2003. It is a fast-paced shooter that makes heavy use of Direct3D.

The general trend we saw with CoD and JK2 seems to change at this point. All of the cards start out in a tightly-knit pack at 1024x768 and no AA/AF, and then fan out slightly at 1600x1200, with the 6800 leading the pack. With 4xAA/8xAF, the NVIDIA cards all scale in the same fashion, with the 6800 besting the 6600 GT by an average of 6 FPS. The 9800 XT starts gaining momentum at 1280x1024, and finally finishes almost 30 FPS ahead of the competition at 1600x1200. The 256 MB of memory really pays off in UT2004 when AA/AF are in use. Performance on the 6800 remains at playable levels on all resolutions with no AA/AF, and manages to stay playable up to 1280x1024 with 4xAA/8xAF. At 1600x1200, 4xAA/8xAF are not recommended for any of the NVIDIA cards.
Halo
Halo, while not being the newest of games, still manages to bring some video cards to their knees when paired with a high resolution and AA/AF.

Overall, not too shabby a showing in this game for the 6800, except where 1600x1200 is concerned. It's interesting to note that the 6600GT scores ~10 FPS higher on average with 8xAF than the 6800 with no AF. Resolutions of 1024x768 and lower with 8xAF ought to be very playable, but anything higher and performance may drop to sub-playable levels under heavy action.