I bought a GTX 660 SC on ebay new for 200$ and a few days later learned the competitor is a radeon 7950. I looked on new egg and for 25$ more i could have got the radeon that has 1 gb more gddr5 and is 384 bit on top of 3 free games . I noticed though the core clock and memory clock are both considerably lower than the 660 SC, so my question is how much better(or worse) is the HD7950.
In short: AMD offers more performance, but the 660 offers Physx. Honestly, the 7950 is the better option, but its not really warranting a return as you will probably need to pay to return. Either is a good buy, but the 7950 is better.