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. The results for Batman Arkham City with GPU PhysX, Crysis 2 with tessellation and Project Cars haven’t been taken into account for the index.
We set an index of 100 to the GeForce GTX 580 at 1920x1080:
The Radeon HD 7950 outperforms the GeForce GTX 580 by 6% on average and the Radeon HD 6970 by 17%.
Its processing performance is 24% down on the Radeon HD 7970 and this has an impact of 14% on performance in practice, the Radeon HD 7950 benefitting from the fact that its pixel and triangle rate and memory bandwidth have been reduced to a lesser extent.
Note that the latest drivers from AMD increase the performance of the Radeon HD 7970 by 1.3% on average in comparison to the figures we got during our previous tests.
We noted something with the Radeons in all these tests: they 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
. Although there might be technical reasons for this, we imagine that AMD has reduced its optimisation efforts, preferring to highlight the antialiasing carried out during post processing, such as FXAA or MLAA, which is simpler to support.