The tessellation question
Hardware-based tessellation is a cornerstone of DX11. The ability to efficiently generate massive geometry and then to apply what's known as a displacement map to it makes it an alluring technique for adding complexity and detail to a scene.Unigine's Heaven 2.0 benchmark tests the ability of DX11 GPUs to provide varying levels of tessellation and extra in-benchmark detail.
Here's the standard benchmark run at 1,920x1,200 with 4x AA and 16x AF. No tessellation is activated.
The scene looks good enough, right, but it could do with some extra tessellation-generated detail, so here's the same benchmark with tessellation switched to moderate.
We see a lot more geometry being used. The flagstones have depth and the steps on the right-hand side are well-defined.
The above shot shows tessellation set to 'normal'. We can't see too much of a difference between moderate and normal, can you?
The Extreme settings provides greater tessellation at a distance. See how the orange roof has greater detail?
We ran four DX11 cards through the tessellation test at each setting.
Benchmarks
The
difference between no tessellation and moderate tessellation is
obvious. GeForce GTX 480 loses less performance than the Radeon GPUs.
Normal
tessellation takes off around 10 per cent performance for little visual
gain. The gap between the best two single-GPU is 40 per cent.
GTX 480 finally wins when the benchmark is set to Extreme mode. Why? Because of the aforementioned focus on geometry performance via GPU-wide PolyMorph engines, and geometry is one area where GF100 is particularly strong.
However, the Radeons do a decent-enough job with moderate tessellation.