You're going to be bottlenecked by both your ram and your cpu. As said before, you're gonna want at least 4gb of ram (needing more than that depends on the specific applications you run, 4gb is plenty for gaming). You're also gonna want to upgrade your cpu, a phenom II or i5 will give you a nice performance boost. For comparison, with my 4870 and a 720be I max every setting in that game @ 1680x1050 and never drop below 60 fps.