ATi adopted a different approach to Nvidia for its most recent top-end graphics card. Rather than coming up with a completely new GPU from scratch to compete with the 8800 series of cards, the manufacturer 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 part, equipped with a combined 1333 million transistors and a whopping 640 stream processors – compare that with the 128 stream processors of the 8800 cards 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 1280 x 1024 and Medium settings putting the X2 just behind the 8800 GTX with 56fps. But when we upped that to 1600 x 1200 with High settings, it impressed with 31fps.
The Call of Juarez DirectX 10 test was more telling: at 1280 x 1024 the X2 more than doubled the Ultra’s 49fps, and still managed an incredible 77fps at 1600 x 1200. Finally, an average of 64fps at 1920 x 1200 (against the Ultra’s 36fps) shows just how well the X2 deals with high resolutions.
It was all going well until Nvidia’s new cards arrived. The $145-cheaper 9800 GTX rivalled it for performance. Then, the 9800 GX2, which also has two GPUs on one card, trounced it in every test.
The3870 X2 still represents fairly good money for the performance on offer, but its kudos-laden fastest card crown has been firmly wrestled away by Nvidia.
This article appeared in the June, 2008 issue of PC Authority.