A gtx 650 outperform a Radeon hd 6670 by how much?

[TheEveryDayProblem]

Apparently, my local shop are selling some zotac gtx 650 for 60$ estimated. At the same time they're selling some asus hd 6670 for 45 $ . I've compared these 2 gpu by looking spec online but they weren't enough to convince me. I mean hd 6670 have 768 gflops. And gtx 650 have 812 gflops. So paying more for just a little bit of performance isn't that good. I want to hear it from you guys.
I'm really concern about this because i want a gpu fast for my asus p5p41c motherboard, It's has been sitting in the corner for quite a time.

 

[Alan Caldwell]

Specs? The GTX 650 would be better.

 

[TerryLaze]

The 650 also allows shadowplay and runs dx12 games has less driver overhead and probably consumes less power as well.

 

[Plumboby]

running an asus 650ti gtx in an i3 haswell set up the quality of the nvidia cards is much nicer & longevity will outlast & preform over any amd cards less heat better over clock can play most new release games as proven here no isuues use msi afterburner with the nvidia card u be happy for many years i am a nvidia fan boy for gaming the way to go good fps good support the cards are more powerfull than the specs on paper go with the 650 gtx u pay a bit more but u be happier the safe way & its quality & nicers chipsets & dont need power to run them