XFX R7950 Black Edition Review
XFX R7950 Black Edition with Dual Dissipation Cooler
Catalyst HD7970 Drivers 11.12
Intel Core i7-3960X @ 4GHz
ASUS Rampage IV Extreme
Windows 7 Ultimate x64
As you can see the XFX comes out the box a lot faster than the reference card. Although it overclocks as easily as the HIS did it tops out at 25MHz less on both the GPU and Memory. So we should see much better stock performance and perhaps a tiny drop-off in the overclocks.
What a difference a cooler can make. At idle the XFX is comprehensively cooler than the reference design, and even the overclock doesn't overload the Ghost coolers capabilities.