With patch 1.2, Crysis has a very heavy CPU bench (to be found in the Bin32/Bin64 directory). The test was carried out at high settings, but at a res of 800x600 so as to limit dependence on the graphics card.
While up till now we only thought we were limited by the GPU, the Sandy Bridge CPUs allowed us to get beyond the limit to a bit less than 31 frames per second in this very heavy scene. What really lies behind this is difficult to determine however.
New to our test protocol, Arma 2 is configured with all settings at a max including max visibility (10 km), which brings the configurations to their knees. Resolution stays at 800x600 to avoid the graphics card impacting on performance. To gauge performance we measure the framerate during a well-defined movement after having loaded a saved game.
As of the Core i5-2400, the Sandy Bridges are up there with the fastest LGA 1366 processors. The 2500s and 2600s widen the gap.