Remove the overclocking out of the picture and the HIS HD 7970 is everything you'd expect from a reference card and this is ultimately a good thing as the out of the box performance on the HD 7970 is great and from a technology stand point, we've got lots of improvements and tweaks across the board.
Stepping away from the reference clocks, though, for a moment and checking out the overclock we've got, we're able to see the kind of potential we're able to get out of the model using just the reference cooler. What's important to note is that the overclock we're running today is 100% stable in all of our benchmarks.
This is important to note - we've seen sites bench as over 1200MHz on the core, we did it ourselves with the XFX HD 7970 Black Edition Double Dissipation, but we ran the fan at 100% and the only benchmark we did was 3DMark 11. When it comes to benchmarking other games you'll quickly find that your max clock in 3DMark 11 isn't exactly stable for everything.
Around the 1100 / 6100 QDR mark should be fairly reachable by most people. At this level you should also find that everything is playable at 2560 x 1600 at a solid 60 FPS. This is going to come at the cost of some extra heat, power draw and noise, but if you want to stretch the performance of your new HD 7970 even further, it's a good option.
If you want to just do some flat out benchmarking, then you can crank that fan speed up to an unbearable 100% and crank the clocks even further. With the overclocking range of the card, you can have a real blast doing some 3DMark 11 benchmarking because of the massive jump in score you're able to achieve when compared to the out of the box clocks.
If you want to get in on the HD 7970 action, you really can't go wrong with the HIS offering today. We really look forward to seeing what the company does later on, though, as they'll no doubt expand the popular IceQ line of cards with this new GPU from AMD.