Back when we looked at AMD's Radeon HD 3870 X2 we mentioned that in the near future new drivers should be made available enabling what AMD calls CrossFire X, adding CrossFire support for more than two GPUs. Well, the future is now here and as of Catalyst release 8.3 CrossFire X has arrived.
Specifically support is available for the 3800-series of cards, which comprises the Redeon HD 3850, Radeon HD 3870 and Radeon HD 3870 X2. An interesting feature of CrossFire X is that you don't need to have exactly the same cards, so a 3870 X2 will work with a single 3870 in a 3-way setup.
Different combinations of memory configuration and clock speeds can also be joined, although everything will work to the lowest common denominator. Basically you're going to want to keep everything as similar as possible so as not to be wasting performance.
Catalyst 8.3 also brings support for Hybrid CrossFire on the 780G platform. If you recall this allows a Radon HD 3450 card to be added to the rendering power of the integrated graphics - although as we've mentioned already, don't expect stellar performance.
Other than those additions, the new driver also adds a few performance tweaks for games such as Crysis and Company of Heroes. Of course whether those boosts are in real world scenarios or canned benchmarks is a matter for debate, but some benefit should at least be seen.
So, what are you waiting for? Get downloading!