Crossfire X is the combination of several Radeon graphics cards. PCGH checked how different variations are scaling.
If you want to use Crossfire X the range of available motherboards is bigger than it is for Nvidia's SLI: Both AMD and Intel chipsets support the Multi GPU technology.
In order to receive an optimized test setup, we used an AMD 790FX motherboard with 2 GiByte RAM and put a Phenom 9950 BE on top. Furthermore the 32 bit version of Windows Vista was the operating system of our choice and all graphics cards were tested with the latest Catalyst 8.7. Triple Crossfire was benched with the HD 4870, while the combination of two HD 3870 X2 (the HD 4870 X2 wasn't available for this review yet) delivered four GPUs.
The results of Crysis and World in Conflict reveal: AMD's solution doesn't always scale perfectly with increasing numbers of graphics processors. It is even possible that three GPUs are faster than four - this looks like the driver needs some more optimization.
Cryis: In this setup Triple Crossfire is slower than the simple versions with two cards.World in Conflict delivers better results. The technology is working as it is expected to.Crysis with up to four GPUs: the calibration between the chips is slowing the system down again.