Labs

ATi has adopted a different approachto Nvidia for its most recent top-end graphics card. Rather than coming up with a completely new GPU from scratch to compete with the superb 8800 series of cards, the manufacturer has decided simply to cram two mid-range HD 3870s onto one board - and the result is surprisingly effective.

The two GPUs essentially make it a CrossFire setup, although you don't need a CrossFire motherboard because it only uses the one PCI Express slot. The four GPU limit still applies, so you can only put two X2s in a PC rather than four, but with performance like this we can't see that being an issue.

Like the HD 3870, it's a 55nm

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part, equipped with a combined 1,333 million transistors and a whopping 640 stream processors - compare that with the 128 stream processors of the 8800 Ultra and you'll begin to grasp this card's muscle. It's clocked slightly faster than the single HD 3870, at 825MHz, and comes with a combined 1GB of GDDR3 memory, running at 900MHz.

Its strength wasn't initially evident in our tests, with Crysis at 1,280 x 1,024 and Medium settings putting the X2 just behind the Ultra with 56fps. But when we upped that to 1,600 x 1,200 with High settings, the two drew neck-and-neck on 31fps.

The Call of Juarez DirectX 10 test was more telling: at 1,280 x 1,024 the X2 more than doubled the Ultra's 49fps, and still managed an incredible 77fps at 1,600 x 1,200. Finally, an average of 64fps at 1,920 x 1,200 (against the Ultra's 36fps) shows just how well the X2 deals with high resolutions.

It remains to be seen what Nvidia has planned as a comeback- a faster GeForce chip surely sits in storage, ready for this very moment, and the forthcoming 9800 cards may yet steal back the crown.

But for now, ATi can bask in much-needed glory, and the price - just £238 compared with £340 for the Ultra- makes the X2 even more attractive.