SuperTiling performance
Here's a completely loony test that I just had to try. I turned off Catalyst A.I., effectively forcing the CrossFire cards into SuperTiling mode, to see how they would perform.

The SuperTiling CrossFire rig is really pokey in 3DMark05's three game tests, even slower than a single card. This performance is pretty well consistent with what we saw in the F.E.A.R. demo and Guild Wars, where turning on CrossFire was a net performance loss. These results can't be encouraging for those pinning their hopes on CrossFire "just working" in any 3D game.

The three synthetic pixel-pushing tests above confirm that SuperTiling is indeed working correctly; the basic fill rate and pixel shading power of the two Radeon X850 XT cards is evident.

SuperTiling doesn't help vertex processing performance, just as expected. The SuperTiling setup performs like a single card in the vertex shader tests. The CrossFire rig must normally run in AFR mode in 3DMark05.