I couldn't find any direct comparisons but I believe (2) GTX 260's slightly outperform a GTX 480. So you really are not gaining anything. The 260 is a direct competitor of the ATI 4870. (2) of these runs around what a GTX 480 would. Depends what game you are benching and what not. The only thing you would really gain is DX11, which isn't really a good reason. I'd hold onto them for another round of cards until a single card outperforms your pair be a compelling amount, or upgrade to another dual card setup. Maybe when the GTX560, or 570's come out.