well, i doubt you're processor would differ much in performance from mine even if its the 65nm core (i have a 4600X2 90nm Windsor). with that in mind, the only game i can't run at maximum settings is Crysis. everything else runs great (30 fps average or better), including games like Gears of War, Bioshock, Mass Effect, STALKER, and TES:IV Oblivion. keep in mind that i'm also running all of those games on either 1900x1080 or 1900x1200 resolution.
CPU - Athlon 4600X2
graphics - Radeon 2900 Pro (soon to be replaced, though)
RAM - 2GB DDR2-800
i also have a sound card which helps take some of the strain of the CPU as well at least with audio processing.
anyways, i hope that gives you an idea of what you can do with your present system. granted, i can't really make much in recommendations till i know what your full PC specs are, but at least you can get in the ballpark.