in the 3dmark firestrike benchmark the gtx960 posts an average of 7700 for a gpu score while the gtx780 posts an average of 10500. that is a pretty big difference. the witcher 3 is a game the gtx960 will close the gap on the gtx780 since there is/was a known kepler architecture issue with performance in that particular game. i think i remember reading somewhere that the 780 only had a 2-3fps advantage over the maxwell gtx960. in practice though with new titles like doom 4 the gtx960 is probably only 15-20% behind in performance as it has more matured drivers.