Quote:
GTX 670 OC has no chance against a HD 7970 OC pushed t0 1200+ clocks. HD 7970 OC will beat GTX 680 OC too when compared across a wide range of games. Have a look at the Sapphire HD 7970 OC at USD 479.
http://hardocp.com/article/2012/04/10/sapphire_hd_7970_oc_edition_video_card_review/4
"The NVIDIA GeForce GTX 680 had a hand up in performance on the stock Sapphire HD 7970 in every game. The Overclocked Sapphire HD 7970 OC Edition crushed the GeForce GTX 680 though in every game providing the best performance and gameplay experience. "
Also this review tested just 5 games. Demanding games like Crysis games (1 / wh / 2) , Metro 2033, Alan Wake, Witcher 2 all run faster on HD 7970 OC compared to GTX 680 OC.
The only thing that might concern you is coil whine. But thats not just with this card. Other cards too have it. One of the users in newegg said setting vsync resolved the roblem for him. best case your card does not have much coil whine. worst case you might have to get RMA.
XFX Radeon HD 7970 DD Black edition is also a good card. But its price has gone upto USD 549. Not a particularly good price.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150586
The first user review on the page says the card does not cross 75c under heavy overclock. anandtech review also says the coolin on this card is good.
http://www.anandtech.com/show/5314/xfxs-radeon-hd-7970-black-edition-double-dissipation-the-first-semicustom-7970/2
Gigabyte has a decent card at USD 499.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125413
Take your pick








