ATI’s onslaught of new GPUs has been unrelenting since September with no less than five different DirectX 11 offerings from the red team arriving in just a few short months. ATI has filled out the 5700 and 5800 series with a range of cards from the £100 Radeon HD 5750 to the £500 multi-GPU goliath Radeon HD 5970.
While supply problems have made many of these cards hard to get hold of, those who have managed to buy them have, like us, been pleasantly surprised with single card performance from all the offerings - bar the painfully overpriced HD 5750 and HD 5970. So far though we’ve only looked at single card performance from ATI’s latest so today we’re taking a look at multi-GPU performance from the three best cards in ATI’s latest range. The HD 5870, HD 5850 and HD 5770 are all decent choices at their respective price points, competing well with Nvidia’s similarly priced alternatives on fps performance while also offering DX11 compatibility and the excellent low power consumption that’s come to define this series of 40nm GPUs.
Click to enlarge - Do two HD 5850s beat a HD 5970?
It's still rare that multi-GPU is worth recommending, but there are times that it makes sense. Two GeForce GTX 260s in SLI, for instance, were able to rival a GTX 295 at a significantly cheaper price. Given that the HD 5970 remains hugely expensive, and with affordable cards such as the HD 5770 offering DX11 support for a reasonable price, could we see a Crossfire setup able to rival the HD 5970 but at a healthy discount?
Multi-GPU performance is complicated though. Time and again we’ve seen that the crucial factor is the driver orchestrating the technomancy behind the scenes rather than the raw power of the cards occupying your PCI-E slots. Considering the significant additional investment involved in CrossFire, we’ll be looking for decent FPS returns and this will be almost entirely down to the quality of ATI’s CrossFire driver.
Some Points On Testing
For this update we’ve tested ATI’s latest batch of single GPU cards in both single and dual card setups to clearly demonstrate the performance gains or disadvantages involved with CrossFire. We’ve omitted the HD 5750 however, which as the lowliest of ATI’s current crop is the least enticing to enthusiasts, especially as it’s badly priced at around £100, only £20 less than the far superior HD 5770.
We’ve also included Nvidia’s GTX 295, and the GTX 285 in both single and SLI configurations. This is more for driver comparison purposes - i.e. to demonstrate the effectiveness of Nvidia’s SLI drivers in comparison to ATI’s Catalysts - rather than as another product to consider buying, as the GTX 285 is now extremely scarce on etailers' shelves. With the first Fermi cards now looking to have slipped into 2010 it seems ATI will have the DX11 graphics market to itself for a little longer yet.
On the point of Catalyst drivers, we’ve used Catalyst 9.10 as the principle driver for our testing, with release drivers for the HD 5970 and Catalyst 9.11’s for the HD 5770 (as 9.10’s don’t support this card). However, as 9.11 only lists bug and compatibility fixes in its changelog and not performance improvements, this shouldn’t affect in-game performance.