It took Nvidia a while to release another dual-GPU graphics card after the awesome 7950 GX2, the fastest DirectX 9 graphics card ever produced. Despite its confusing 9-series name, the 9800 GX2 comprises two G92 GPUs, the same as used in 512MB 8800 GTS.
Unlike the 7950 GX2, the GPUs on the 9800 GX2 are positioned on separate PCBs facing each other, and are encased in a square black plastic box. As a result, the 9800 GX2 looks less distinguished than earlier high-end graphics cards.
Each 600MHz GPU has 128 stream processors and is accompanied by 512MB of GDDR3 speeding along at 1GHz (2GHz effective). The two GPUs communicate with one another through a PCI-E bridge chip on the PCB, so the 9800 GX2 doesn't require an SLI-compatible motherboard, unless you're insane and plan on using two cards in Quad SLI.
The performance of any dual-GPU graphics card depends on the availability of up-to-date drivers and multi-GPU-friendly games. The 9800 GX2 currently does a good job of running three of our test games, X3: Terran Conflict, Fallout 3 and Far Cry 2; it can play all but the latter game smoothly at 1,920 x 1,200 with 4x AA and 8x AF. Far Cry 2 was playable at 1,680 x 1,050 with 2x AA, but Crysis Warhead proved to be too much for the 9800 GX2, even at 1,280 x 1,024 with 2x AA. This is very disappointing, but not a great surprise - neither Crysis nor Crysis Warhead is particularly multi-GPU friendly, despite needing more rendering power than other games.
Unlike ATI's dual-GPU cards, the 9800 GX2 performs like a turbocharged Formula 1 racing car in Folding@home. This is thanks to the ability to disable SLI in the driver and treat each GPU as a separate processor. We measured the 9800 GX2's folding output as an incredible 9,217ppd - nearly three times that of the HD 4870 X2. No other card can come close to matching this output, so it's a great shame that Nvidia discontinued it so quickly in favour of the disappointing GTX 280.
If you're lucky enough to own a 9800 GX2, we'd recommend holding on to it for now, as the only card that's fast enough to justify its price difference is the hot-running HD 4870 X2. Even then, it's hard to justify spending around £350 to be able to play Crysis Warhead smoothly.
Author: James Gorbold & Mark Mackay
Custom PC Online