hd 5970 vs gtx 760

The 5970 is a dual GPU which performs close to a 7950. The 760 itself runs cooler and more efficiently than the 5970 so the 760 would be the ideal choice.

The 760 should be a little quicker and shouldn't have any of the problems the 5970 has in terms of being a dual GPU (like microstuttering etc.). It's always a good idea to go with newer tech so the 760 should be the best choice for you and the price difference between the two isn't too big either.