Nice article. I would have liked to have seen for the first GPU benchmarks the 6990+6970 Tri-fire since you have the tri-sli 580s in that comparison.
Yea, that was completely my fault, I apologize. When the third monitor came in I got all excited, set up tri-fire and just ran them for the Eyefinity benchmark, totally forgetting to run it for 1080p. Currently I'm excessively busy but I'll try to do that sometime soon and report back.
That said, Crossfire scaling is
excellent in this game. The 6970 to 6990 gained 89.8% at 1080p. Adding the 6970 to the 6990 in Eyefinity gained 45.3%, so the fact that it's connected via a bridge instead of Crossfire-on-a-stick doesn't seem to hurt anything.
Based on those two numbers, it wouldn't be unreasonable to expect a similar 45% gain on 1080p also, so with the 6990 getting 89.6 FPS at stock, you'd be somewhere around 130 FPS with a 45% gain. It wouldn't beat the Tri-SLI 580's, but would get close and cost a heck of a lot less (~$1,500 for three 580's vs. ~$1,030 for 6990+6970).