The 6800 is a few FPS more, and when you put up the AA, AF and the resolutoin, the gap gets bigger, about 10fps.
Don't forget that the 6800nu has 4 pipelines locked, so you can get 16 pipelines, and a overclock, could get it up to the gt, maybe even ultra speeds (assuming it has gddr3 memory, but it still could get its normal memory faster, and the core higher.)
Don't forget that the 6800nu has 4 pipelines locked, so you can get 16 pipelines, and a overclock, could get it up to the gt, maybe even ultra speeds (assuming it has gddr3 memory, but it still could get its normal memory faster, and the core higher.)