There are six tests in 3DMark 11. The four graphics tests use advanced rendering techniques to compile the scene including tessellation, volumetric lighting, depth of field and post processing effects. The physics test uses rigid body simulation to stress the CPU while the combined test features CPU and GPU workloads. The CPU handles rigid-body physics while the GPU is tasked with volumetric lighting, tessellation, post processing as well as simulating soft-body physics using DirectCompute.
Performance Settings - Benchmarks Only
This looks a little more realistic and is likely due to a lack of driver optimizations due to 3DMark 11 being and older benchmark. Many reviewers ditch the old benchmarks despite being relevant for performance testing and this shows pure power of each GPU and how similar they are with DX11.