The chaps over HardOCP have the GTX 460 SLI going head to head with a Radeon HD 5870 CrossFireX and the results are very impressive. Here's a taster:

GeForce GTX 460 1GB SLI real world gaming performance is superior to even AMD's fastest high-end single GPU video cards in a CrossFireX configuration. And do keep in mind this is real gaming, not benchmarks. There is no getting around or denying the awesome performance of SLI configured GTX 460 1GB video cards. The excitement is even more pronounced when you can find very highly overclocked GTX 460 cards like the Galaxy GTX 460 1GB Super OC for $229 after $10 MIR. These cards simply represent a great value for the gamer and hardware enthusiast.

We've found previously that GeForce GTX 480 SLI provides tremendous performance well out pacing Radeon HD 5870 CFX in pretty much every newer game released (and we have a follow-up on that coming soon). You can see here where specifically in AvP, that GTX 480 SLI destroys 5870 2GB CFX. So maybe we should not be surprised by what we are seeing here. It seems, that GTX 480 SLI is not the real competition for 5870 CFX after all, it seems that these much less expensive GTX 460 1GB video cards are the 5870 GPU's real competition. AMD should be worried about this. CrossFireX scaling needs some work....a lot of work. SLI is blowing CrossFireX out of the water with these newer GPUs.