NVIDIA Corp.'s multi-GPU technology has been on the market for almost a year, whereas ATI's CrossFire has been available for just weeks now. While NVIDIA is currently dominating on the market, it continues to improve and innovate its Scalable Link Interface (SLI)

Standard PCI Express-compatible graphics cards utilize 16 PCI Express lanes. At the same time, if two graphics cards are put into a multi-GPU setup, both CrossFire- and SLI-ready mainboards immediately divide the x16 link into a pair of x8 ones. This action decreases bandwidth and theoretically may influence overall graphics cards performance negatively. In order to avoid this, the new generation multi-GPU capable platforms are going to provide two fully fledged PCI Express x16 slots.

AMDZone has managed to NVIDIA nForce4 SLI mainboard and compared performance of ATI's RADEON X850 XT in CrossFire, NVIDIA's standard SLI and updated SLI multi-GPU platforms.

?span>So we have quite a bit of new data from this comparison of Crossfire versus SLI and 16X SLI.?Starting with 16X SLI we do see some situations where the extra bandwidth is being utilized.?Truth be told we really could use more data, and we are working on additional benchmarks to find if we have situations yet with this newest generations of games where it can be put to good work.?It was said that 512MB were a waste of money, and we found that Call of Duty 2 could use them to great results, and we have a feeling that 16X SLI will find its killer app,?concludes AMDNow.

?span>Considering the entire performance picture of each SLI version and CrossFire initial results are somewhat mixed, but right now lets focus solely on 3D performance.?First bear in mind that we don't yet have 7800GTX SLI numbers, and are relying on 7800GT.?The GTX would likely win every test here.?That noted in general we find SLI to lead in performance, and certainly as AA and AF are cranked up that lead increases.?Without AFR support for the new games of Quake 4 and F.E.A.R. CrossFire stands no chance compared to SLI that works with both out of the box unpatched.?Also with the real benefit of dual graphics showing at very high resolutions CrossFire's limit to 1600X1200 resolution at 60Hz puts a hurt on if you have a 23?or 24?widescreen,?adds the author.

• AMDZone: Dual Graphics Card Showdown: CrossFire vs SLI vs 16x SLI.