MSI GeForce 9800 GX2 in Graphics cards

Nvidia's high-end cards dominated the graphics market throughout last year, so it's interesting to see them now taking a leaf out of ATi's book. Rather than offering a super-fast version of their flagship G92 GPU, they've produced a single card running two of them in parallel. (In fairness, the idea was Nvidia's to start with: they released the first dual-GPU card, the GeForce 7950 GX2, back in 2006.)

Plugging in a GeForce 9800 GX2 is effectively the same as installing two 9800 GTXs in a standard SLI configuration. But that doesn't mean it's twice as fast as a 9800 GTX - running GPUs in parallel involves the same technical challenges as with CPUs. Indeed, in light use, the second GPU is entirely redundant: the GX2 scored identically to the GTX in our low-detail Crysis tests, and even at 1,600 x 1,200 with high detail it merely matched the GTX's 32fps average.

But, as we found with ATi's Radeon HD 3870 X2, when we turned the detail settings up to Very High the GX2 came into its own, keeping up a playable 28fps, while the GTX fell to 17. The game was even playable, albeit juddery, at 1,920 x 1,200 with very high detail, averaging 23fps.

At £359 exc VAT, MSI's GX2 board is one of the more expensive models out there. Shop around and you'll find competing GX2 cards for £40 less, but even those are a pricey proposition next to the HD 3870 X2. That card now sells for around £230 exc VAT, but did just as well as the GX2 in our High detail Crysis test. As with the GTX, however, the ATi can't keep up at very high detail: while the GX2 held up 28fps, the 3870 X2 fell to just 21fps.

There's no denying that the dual-GPU approach is an inefficient one. The 9800 GX2 is a huge card demanding two power connectors, and Nvidia recommends at least a 580W power supply. And, unlike the Radeon, which will run at stock speeds on two six-pin connectors, you'll need both a six-pin and an eight-pin connector to get the GX2 going. Thermal design power (TDP) is high too at 197W, so the usual large fans are present.

But while it may have had to resort to brute force to do it, Nvidia has convincingly regained the performance high ground. For casual gamers, a more affordable card makes more sense, and even if you demand the very best in graphics there are currently cheaper GX2-based cards than this. Nevertheless, if you have a large enough monitor (24in) to take full advantage, the GX2 puts Nvidia back on top.

Author: Darien Graham-Smith