We can see that the GeForce GTX 480 and faster configurations are bumping into a CPU bottleneck in Far Cry 2. Aside from that, this game engine seems to favor GeForce solutions when 8x anti-aliasing (AA) is enabled.
At the high 2560x1600 resolution, the Radeon cards in CrossFire suffer a substantial performance hit, and the GeForce GTX 460 in SLI provides a lower minimum frame rate than expected. It’s probable that some of the blame can be placed on the cards’ 1 GB frame buffer compared to the 1280 MB on the GeForce GTX 470 and the 1536 MB on the GeForce GTX 480. In support of the RAM theory, we saw the 4 GB Asus Ares—essentially two 2 GB Radeon HD 5870s in CrossFire on a card--perform slightly better than the GeForce GTX 480 in this benchmark at this resolution with 8x AA applied.