Conclusion

AMD's CrossFire is scaling better than nVidia's SLI looking at both synthetic (5%) and games (0-2 %) benchmarks in average. When you look closer at the different benchmarks, one by one, AMD is doing a better job for the scaling than nVidia. It was quite often that we had a very close to 200 % improvement. But there is a dark side - that's why on average the scaling is very close to nVidia - CrossFire is not always working well. For exemple as you may have seen in the graphs under Batman and Skyrim - which are quite old now - drivers should be optimized. Reality shows that they haven't been optimized and there is a downscaling with CrossFire, which means that with two cards the performance was worse than with one card. This gives AMD a big disadvantage. On the other hand we didn't have any problems with SLI, it was working well with all games we tested.

Looking at the performance index you clearly see that the GTX 680 SLI is the fastest dual graphics solution. Now from a performance/watts point of view new nVidia graphics card are clearly winning. As for the price/performance ratio at the moment both HD 7950 and GTX 670 are at the same level offering the best performance/price ratio. Then comes the HD 7970 and the GTX 680 not that far behind.

So the best single card at the moment from all those points of view is clearly the GTX 670 which is dominating. Now for those who want pure performance not looking at the price or power consumption the GTX 680 SLI is clearly the best choice.