AMD Radeon HD 7970 3GB GHz Edition Review
When the HD 7970 and its Graphics Core Next architecture were first introduced, AMD's loyal fans had many reasons to celebrate. The high end 28nm Tahiti XT core was able to significantly outperform every NVIDIA card on the market and the follow up Tahihi Pro-based HD 7950 added a strong value-oriented product as well. Some initially whined about sky high prices of $549 and $449 respectively while others were concerned about rampant power consumption (ironically, NVIDIA had struggled with both of these points a generation earlier) but no matter which way you looked at it, AMD was on the top of the world. And then came Kepler.
In many ways, the first Kepler-based cards –the GTX 680 and GTX 670- moved the market’s goal posts by essentially bucking NVIDIA’s trend of releasing hot, power hungry and physically massive cores. In their place was an efficient architecture which performed exceedingly well in many titles by primarily focusing upon gaming. GPGPU compute was left by the wayside but Kepler still retained enough power to muscle through most mass market CUDA and OpenCL applications. More importantly, NVIDIA did the unthinkable and undercut the HD 7970’s price with a higher performing product, causing a nightmare scenario for AMD.
The GTX 680 was a hit from the very beginning but its popularity acted as a double edged sword as production never really kept up with demand and up until recently NVIDIA was still struggling to work through the backorder queues. After months of playing a wait-and-see game, AMD is now ready to launch yet another shot at the GPU performance crown with their new HD 7970 GHz Edition.
Much like the other “GHz Editions” in AMD’s lineup, the HD 7970 version packs a core clock of 1000MHz, representing a 75MHz increase over the version released six months ago. There’s a Boost Clock of an additional 50MHz as well but we’ll get into that on the next page. Memory speeds have been pushed to 6 Gbps and when paired up with 3GB on a 384-bit bus allows for a vertigo inducing bandwidth of 288 GB/s.
So why release this card now instead of initially offering the HD 7970 with a 1 GHz core clock and higher memory speeds? AMD’s way of explaining this was quite simple: when the Tahiti cores were first brought to market, the 28nm manufacturing process was very much in its infancy. As such, certain concessions had to be implemented in order to keep power consumption and heat output within a given envelope. As the process gradually matured, AMD took the lessons learned with Tahiti and rolled improvements into the HD 7870 and HD 7770 GHz Editions. Now we’ve come full circle as the refinements are being cascaded back up into the enthusiast range without any changes to the underlying architecture. Memory technology has also improved since the components were chosen for the first Tahiti XT cards so AMD decided up upgrade the GDDR5 modules using 6Gbps ICs.
As overclockers know, all of the improvements we listed above were possible with the original HD 7970 albeit with a corresponding increase in power consumption and heat output. The GHz Edition and its relative architectural maturity allows for higher clock speeds while maintaining a 250W power requirement of its predecessor. Some would call this the natural evolution of an architecture but to us its progress brought about by healthy competition.
There is something we need to bring up here and now. Unlike the “reference” version sent to reviewers, board partners aren’t obligated to include 6Gbps memory for their product to be considered a “GHz Edition”. This raises a serious question as to whether or not retail cards will replicate the performance you see in this review. Some AiBs may actually release similarly spec’d cards but several we have talked to have no intention of modifying their lineup for the time being since they already have custom HD 7970 SKUs clocked at 1GHz and higher.
Two factors which will define this product from the outset are price and availability but at this point, only one is somewhat set in stone. According to AMD, the HD 7970 GHz Edition will hit retailers’ shelves at the $499 mark which puts it in direct competition with NVIDIA’s GTX 680 (if you can find a reference-based $499 GK104 card that is). Availability on the other hand is the big question mark here since none of the board partners we spoke to would commit to a retail availability date and instead chose to say “within the next few weeks” for cards "resembling" the clock speeds of the reference GHz Edition.
As you may have already expected, the reference GHz Edition is a spitting image of its predecessor with a length of 11”, an 8+6 pin power connector input and a great looking red and black colour scheme. It also comes with the usual dual BIOS switch. Why reinvent the wheel when the standard HD 7970 design performed admirably, right?
Also remember that the vast majority of HD 7970 GHz Edition cards will be released as custom versions and won’t be following the reference design you see above. What this means for pricing is anyone’s guess (the $499 price is for the card you see above) but we’ll just have to play a wait and see game until they’re available.
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