kramkat :
but a lot of review says that 660 ti is better than 7950?
what reviews are you talking about?
After the recent few amd driver updates, the hd7950 dominates over the gtx660 ti to the point it even challenges the gtx670 at times.
People debate about gtx670 vs hd7950 nowadays and gtx660 ti is just not in the league
if you are after phys x, you should go for the gtx660 ti