Hd 7850<gtx 650 ti boost(by 3%)< gtx 660. I would get the card that akshayghai reccomended since it will run cooler then the evga. If you want a boost though i would reccomend getting this boost: http://www.newegg.com/Product/Product.aspx?Item=N82E16814127728
It becomes 141 dollars. Overclock it by around 10% and you would be very close to the performance of a gtx 660.