Hi folks, BF3 s out and I need to upgrade, present spec is; Asus M4a79xdt evo motherboard (CF capable), 4 GB DDR3 Ram, Radeon HD5870, Amd Phenom II X4. Should I get a GTX 580 (would it bottleneck?) or should I CF the 5870? I'm not great at building or solving software issues but even I can swap a GPU over I hope. Many thanks.