I have a phenom II x4 955be with gtx260 core216 and I max farcry 2 out 1680x1050 without problem. It never stutters for me. With 8x anti aliasing I average about 30-40fps when just running around. With anti-aliasing off I'm seeing 45-60+. I'm just direct x10 btw.
ME2 also runs great for me too. Not sure why your farcry 2 fps suffers because your system is more powerful than mine. How much fps are you averaging in FC2?