Hello all. Recently purchased a Gigabyte GV-R797OC-3GD 7970 and promptly returned it after discovering it was voltage locked. Doing some research I am lead to believe most of the 7970s in production at the moment are voltage locked. As such, I have turned my attention to perhaps a 7950, which do not appear to be voltage locked, and can thus OC well past a 7970. My question is primarily which 7950s or 7970s are not voltage locked, and should I choose to go with a 7950, which one should I get to allow me to OC it past a 7970. Thanks.