According to statistical data collected by the Steam system, multi-GPU configurations are very far from popular. They are only present in computers of less than 1 percent of all gamers. Interestingly, 96% of such configurations are based on Nvidia’s SLI technology whereas AMD’s CrossFireX only amounts to 4%. Of course, Steam collects data for the limited number of games and applications that it distributes or supports. Even though Steam delivers many bestselling titles, its statistics cannot be viewed as the final truth. On the other hand, there are no other statistical data available on that issue.
It doesn’t take much insight into the market situation to realize that multi-GPU configurations are indeed very, very scarce. There are very few users of two graphics cards on hardware forums and, try as you might, you can’t virtually find any people who build graphics configurations with three or four cards. Besides the obvious reason of high price (including the higher price of compatible mainboards and high-wattage power supplies), the deterring factors are the low stability and efficiency of SLI and CrossFireX subsystems which depend greatly on software optimizations.
However, we have noticed a rather optimistic trend during this year as multi-GPU technologies seem to have improved. This is especially true for CrossFireX which used to have much more stability and efficiency issues than SLI (by the way, the latter technology offers the unique opportunity to choose from different rendering modes in the driver and thus can work in more games). AMD has been really working hard to improve CrossFireX. For example, they have recently introduced CrossFireX profiles to install together with the Catalyst driver and be updated regularly. And like you will see in our today's tests, there are also hardware changes in the new Radeon HD 6850 and 6870 cards.
So, this review is all about the compatibility and efficiency of CrossFireX technology as it is now.
Technical Specifications of the Testing Participants
The graphics cards in the following table as well as on the results diagrams later on are sorted accoridng to their recommended price (from high to low):