I seriously doubt your cpu might struggle to keep up with BF3 but it might run. I had a friend with P4 3.0ghz 2gb 9600GT that runs Battlefield Bad Company 2 on 1360 x 768 @ 30fps on low setting. But since BF3 is more demanding it might struggle. If you had a Core2Duo, say like my old PC Core2Duo 2.4ghz, 2gb ram, 9600GSO it can run BF3 at 1360 x 768 res @30-45fps on low to medium settings. A GTS450 will be enough. Try built a cheap AMD A6 with 4gb ram and a GT430, BF3 can run @30fps on low 1360 x 768