The GeForce 7800 GTX SLI platform boasts a total of 48 pixel pipelines, but its memory is slower than the graphics memory subsystem of the RADEON X1800 XT CrossFire, which also has efficient memory controllers into the bargain. This is why ATI's solution takes the lead in 1280x1024 resolution, leaving the others far behind, and then yields over 70fps in 1600x1200. Both the multi-GPU subsystems perform close to their theoretical maximums, NVIDIA's SLI being as high as 100% efficient in 1600x1200!

It's only in one game, in the 3D shooter Project: Snowblind, that the multi-GPU rendering mode brought about a negative performance gain, and not only with CrossFire but also with SLI. It means that the problem must be in the game rather than in these two technologies. In the majority of applications we have observed a performance growth ranging from 10-20% in F.E.A.R. (probably due to some problems with SuperTiling) to 80-90% in other games. In three more games the speed proved to be limited by the CPU performance despite our using full-screen antialiasing. We were also pleased with excellent stability of the CrossFire platform which never hung up and never produced any image artifacts during our tests. This is another sign of maturity, we guess. ATI CrossFire does work now and it works quite well.

So ATI now offers a working alternative to NVIDIA's SLI, but how appealing this product is? The recommended price of the RADEON X1800 XT CrossFire Edition being $599, the combined cost of the corresponding CrossFire platform will be $1200 - without the mainboard and power supply. This is not too much in comparison with the cost of two GeForce 7800 GTX, which is about $1000. Multi-GPU systems are assembled to make high resolutions with turned-on full-screen antialiasing and anisotropic filtering playable and the RADEON X1800 XT CrossFire looks preferable to the GeForce 7800 GTX SLI in almost all the games we've used in this review. The Super AA 14x mode is available most of the time, while SLI AA 16x, although it does ensure a noticeably higher antialiasing quality, is such a difficult algorithm that the performance of the SLI platform sinks below playable level in nearly every game. Moreover, the RADEON X1800 architecture allows using FSAA and HDR simultaneously, while the GeForce 7 architecture does not.