We used to be rather skeptical about the prospects of multi-GPU subsystems built out of entry-level graphics cards. Their reliance on the game engine’s and driver’s support made them unsuitable for most gamers who were likely to prefer a single top-end graphics card instead. Although this statement is largely true to this day, ATI’s CrossFire and Nvidia’s SLI technologies should be given credit for having gone a long way since their early days and problems with compatibility and performance. Today, these multi-GPU technologies work just fine in a majority of modern and old games and if they fail to do so in a new game, the compatibility issue is usually resolved very quickly.
So, our position on this issue had to be adjusted and the global economic recession impacted it, too. As a result, we have published a series of reviews dedicated to entry-level multi-GPU solutions based on such cards as Radeon HD 4670, Radeon HD 4770 and Radeon HD 4830.
Recently we also reviewed CrossFireX subsystems built out of AMD’s inexpensive Radeon HD 5700 series products, describing symmetric tandems of two Radeon HD 5770 and two Radeon HD 5750 cards. But we know that, unlike the capricious Nvidia SLI technology that might require not only that you use identical graphics cards but also that these cards have identical BIOSes, the ATI CrossFireX technology in its current implementation works just fine on asymmetric configurations. Therefore we want to check out what we can expect from a multi-GPU configuration assembled out of a Radeon HD 5770 and a Radeon HD 5750.
We think there is a practical point in this. CrossFireX-compatible mainboards are widely available and comparable to mainboards with only one PCI Express x16 slot in price. The Radeon HD 5750 can be bought for less than $150 in retail. Thus, if you don’t have $400 or more to spend for a Radeon HD 5870, you can equip your gaming subsystem with a rather cheap but fast Radeon HD 5750 and later add in a more expensive Radeon HD 5770. This combination would have a total of 1520 ALUs, 76 TMUs and 32 RBEs, which is more than what you get from a Radeon HD 5850 but at a price lower than the Radeon HD 5870. The opportunity of building this graphics subsystem in two steps makes it even more appealing.
We’ve got a couple of cards necessary for such a test, an ASUS EAH5770/2DIS/1GD5 and PowerColor PCS HD5750 1GB GDDR5 Premium Edition, and are going to show you how appealing an asymmetric CrossFireX tandem can be. First, let’s take a look at each card of the tandem.