Enemy Territory: Quake Wars
The 878/1,910MHz-clocked Sapphire ATOMIC X2 is around five per cent faster than a regular X2 in Enemy Territory: Quake Wars, and that's consistent across resolutions.
Trouble is, the NVIDIA GPUs are faster, and it makes all the difference if you happen to be playing at 2,560x1,600.
However, just to complicate matters, the three-run results' variance at 2,560x1,600 is such that the ATI cards' numbers fall outside the accepted standard deviation - you take them with a pinch of salt.