Performance recapAlthough individual game results are obviously worth looking at when you want to gauge performance in a specific game, we have also calculated a performance index based on all tests with the same weight for each game. We set an index of 100 to the GeForce GTX 580:
On average, the GeForce GTX 680 outperforms the Radeon HD 7970 by 5.6% across all our tests which offer a mix of different rendering techniques and types of antialiasing. There’s certainly been a very comfortable (almost 30%) gain on the GeForce GTX 580, but this is down on what NVIDIA has got us used to with high-end cards.
It's interesting to note that the GeForce GTX 680, which represents a duo of overclocked GeForce GTX 560 Tis but with limited memory bandwidth, only slightly leads them when in SLI. In comparison to just one of these cards, the advantage is close to 80%.
At very high resolutions, the GeForce GTX 680s perform relatively poorly and are on a par with the Radeon HD 7970. The gain over the GeForce GTX 580 is however up to 35% here at 2560x1600.
While the Radeon HD 7870 CrossFire solution is the most efficient at 5760x1080, it’s important to note that in most games, in contrast to what the performance figures indicate, the fluidity isn’t up to scratch.
We noted in all these tests that the Radeons tend to suffer more than the GeForces when the deferred rendering engines use MSAA. It’s a complex task to use this type of antialiasing in a deferred rendering engine. There’s an example in our report: Understanding 3D rendering step by step with 3DMark 11
. It’s possible that they suffer from a technical limitation here or that AMD hasn’t put as much of an effort into optimisation, preferring to highlight the antialiasing carried out during post processing, such as with FXAA or MLAA which is simpler to support.