Crysis 2 uses a development of the Crysis Warhead engine optimised for efficiency but adds DirectX 11 support via a patch and this can be quite demanding. As, for example, with tessellation, implemented abusively in collaboration with NVIDIA with the aim of causing Radeon performance to plummet. We have already exposed this issue here
We measured performance with Fraps on version 1.9 of the game.
Hold the mouse over the graph to class cards by performance.
In High mode, the GeForces are the most efficient while the Radeons make up ground in Extreme mode.