Play-Doh, Silly Putty, or the title of “the fastest video card in the world”—which is the most malleable? AMD, not willing to cede the last to Nvidia for a whole generation in the wake of its release of the GeForce GTX 680 earlier this spring, has now released its Radeon HD 7970 GHz Edition ($499 list). As its name suggests, this video card is a direct revision of the regular Radeon HD 7970  the company released six months ago, albeit with a clock speed upgrade.  And, yes, it’s enough to nudge AMD’s former flagship card back into the top spot—at least until (presumably) AMD supplants it with a new 8000-series card in several months’ time. So, yes, if you’re looking for the best-performing single-GPU video card you can get right now, this is it.  But it’s neither a perfect product nor a perfect value.

Because there are so few differences between the original 7970 (which will remain available; many versions can be found for about $450) and this new GHz Edition , we’re not going to cover all the same ground again that we did half a year ago—check out that review if you want the basic rundown of everything this particular GPU offers.  Instead, we’re just going to focus on the changes.

First and foremost is, of course, the new 1GHz clock rate.  AMD’s previous cards with the GHz Edition moniker, the Radeon HD 7770  and 7870, used the speed to compensate for fewer stream processors, something the 7970 didn’t need help with (the 2,048 stream processor complement, like many other things, has stayed the same). So the new card’s bump (from 925MHz), though nice, is not an Earth-shattering event.

That is, however, not the only speed improvement.  AMD has augmented this card’s Power Tune technology with a new trait called Boost, which (like similarly named features on previously released AMD and Intel CPUs, and Nvidia video cards) dynamically increases the clock speed still further assuming you have the electrical and thermal headroom to accommodate the uptick.  The key Boost speed here is 1,050MHz; enterprising board partners or private overclockers who devise better cooling solutions can doubtlessly push up the number still further, but this puts a bit of extra free (and no-stress) performance in everyone’s hands.

Memory, too, has received some changes.  Not in the amount—this GHz Edition features the 7970’s same 3GB of GDDR5—but in the speed: The previous card settled for 1,350MHz, and this one goes for 1,500MHz.  This gives the GHz Edition a solid 6Gbps data rate over a 384-bit memory bus—about the same speed Nvidia has boasted in its own newest 600-series cards.