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I got the MSI 7950 http://www.overclockers.co.uk/showproduct.php?prodid=GX-148-MS&groupid=701&catid=56&subcat=1673 from OCUK to replace my 6870 CF setup and im very impressed. I have never had a Nvidia card so i cant comment on these but this MSI version clocks very well. Im running it at 1100/1500 @1.1v and i havent really tweaked with it, i just went straight in at these settings after reading what oter people gad achieved.
7950 all the way.
7950 all the way
Feel like I'm repeating myself tonight, but yeah for price/performance 7950, when paired with voltage tweak they can be made to match an overclocked 670.