I realized those charts showed % scaling with overclock, not absolute peformance in overclocked states. The absolute performance in overclocked states was not plotted by explained in a paragraph instead:
The GeForce GTX 680 2GB overclocked to 1186/7128 MHz is an average 4-11% ahead of the AMD Radeon HD 7970 3GB (overclocked to 1150/7000 MHz) in 1920x1080 and 1-9% ahead in 2560x1600.
That's why I removed the original charts because obviously HD7970 would have higher % increase from overclocking since it's only clocked at 925mhz.
Their reference 7970 hit 1130mhz on 1.17V. They didn't specify what voltage was needed for HD7970 to hit 1150mhz but at 1150mhz their reference HD7970 still consumed 42W more power than a GTX680 @ 1186 with 1304 Turbo Boost. Not a deal breaker for HD7970, but when you also get a
much quieter reference cooler on the GTX680 (from the same review), HD7970's reference cards are awfully unattractive.
@ Xbitlabs, GTX680 at 1186mhz beat 1150mhz HD7970 at both 1080P and 1600P, consumed less power, and did that on a quieter reference cooler for $50 less. This is like Intel's Turbo. You have a base clock + Boost. So when you increase Base Clock, the GPU Boost is on TOP of that.
For example, their GTX680 Base clock was increased to 1186mhz, and because GPU boost is still on, it can often hit between 1277 to 1304mhz with Turbo enabled. :thumbsup: