I think he will be able to play Crysis 2 with settings on "high." You could be right about the CPU's clock rate, but I'll bet it'll still run around 30 FPS. [there is only High - Very High - Extreme settings on Crysis 2, so High is really "Low" if that makes any sense). I only have a HD Radeon 5670 1 GB on my rig and I can play with every thing turned to Very High, and all other selectable settings turned to "ON" - and at 1920 x 1080 resolution. It looks great and it's barely stressing my CPU at all (although I do notice on CPU-Z that it turbos up to 3.4 regulary). FRAPS shows around 60 FPS consistently with no probs.
AMD Phenom II x6 1090T 3.2 GHZ not OC'ed
w/6 GB DDR3 RAM
Try and use dxtory and limit fps to 30.The game runs much smoother then