You can see in the benchmarks that CrossFire will give NVIDIA's SLI a run for its money. However, in applications like 3DMark 2003 and 2005, the scores are impacted by factors other than the actual frames per second. For some reason, the scores do not follow the linear increase in performance that are observed in all of the real world game benchmarks.
When looking at the performance on the various engines, we can see that the rest of the scores are from games doing what they do best: playing. CrossFire in Unreal Tournament almost runs at the same average frame rate as the SLI test system. We are not sure if this can be attributed to the X850 card's native performance in this benchmark, or better utilization of the combined output of the cards. We will be doing another article to look more closely at this technology as its adoption proceeds.
We see a similar trend in games like Far Cry and Doom 3. At a resolution of 1024x768 with the lowest set of features turned on, the CrossFire platform beats the 7800 GTX in the SLI platform. Once the features are turned on and the resolution moves to 1600x1200, the tide turns in favor of the NVIDIA solution. This makes sense, as one of the main goals of the 7800 GTX was to increase the frame rates at higher resolutions.
Finally, we turn to an ATI dominated game, Half Life 2. NVIDIA has never done well in SLI in this benchmark - in fact, it is better to disable SLI and play Half-Life 2 with one NVIDIA card! With this in mind, it is no surprise that ATI in CrossFire configuration dominates the SLI reference system.