GTX 660 OC vs ATI 7850 2GB DDR5 OC

Guys,Which will have better performance with my this config:
PRO:CORE I5 3470
Ram:8GB DDR3 1600mhz
MOBO:GIGABYTE b75 d3v
GPU:GIGABYTE - Graphics Card - NVIDIA - PCI Express Solution - GeForce 600 Series - GV-N660OC-2GD
OR
SAPPHIRE HD 7850 OC 2GB GDDR5
Can't set decide it.Help me guys.
I want to pay for performance not for brand.
Thanks

AMD. The 7850 has 1024 Cores and the GTX 660 has 960 cores. What games will you be playing and at what resolution? Also what is your budget?

GTX 660 Ti will demolish a 7850... but make sure you get the Ti version, which will be a lot more expensive..

I think if he is looking for the 7850 and 660 he is on a budget, I am waiting for an answer

thanks man for reply .I m not going to buy 660 cause ti is very more than my budget.from net searchng what I get that 7850 is best bang for bucks and performance.so no to 660 and will buy 7850.Will get u know about pc config while I will buy iy soon.thanks mate u all again

I dont understand. Oh yeah, no problem.

When I will buy my pc I will let u know guys.hope it help u to understood

Ok, sounds good. Good luck.