That's an odd monitor you have there (1680x1850) jejeje, back to the original question that cpu should give you more fps than that, it's most likely a driver problem, use the latest ati drivers (9.4 I think) and use latest patch for crysis too. You should get at least 25+ fps on gamer settings on 1680x1050, no AA.
I have a q8200 2.33ghz and it does not bottleneck my 4850 at that resolution, but if I use 4850x2 it seems it does. ( I have a 4850x2 and I disable crossfire to just use 1 4850). If I OC to 2.8ghz I can see the increase in performance when using 4850x2 in crysis, but depends of the game you're playing, i.e. if you play GTA IV then your cpu is going to be the bottleneck. because mine is