rs.8600

Nfs series, assassins creed series, cod series, moh, etc......I have shrtlsted 2 cards xfx hd 7770 1gb ddr5 (rs.8600) & xfx gtx 650 1gb ddr5 (rs.7950).....Is hd 6850 better....Plz give some suggestions.....I m going to buy by march 19th...Thnx in advance..