Overclocking and Conclusions

On launch day we hosted AMD’s Evan Groenke for an in-studio live interview and discussion of about the Radeon HD 7970 GHz Edition.  For the on-demand version of that event, check it out right here.  Enjoy!


The process of overclocking the new GHz Edition of the Radeon HD 7970 is mostly the same as the previous model, though you are essentially increasing the maximum boost clock that the GPU is allowed to hit. This can still lead to instability as the voltage changes are still limited.  

For our quick bout of overclocking, I was able to get another 100 MHz out of the card to reach an 1150 MHz GPU clock speed.

That boost in performance nets us another 6.5% in our 3DMark11 score here. We are looking forward to spending some more time with the new GPU – and the boost technology – to see how far we can push it. 


I have to say that I came away from my time with the AMD Radeon HD 7970 3GB GHz Edition graphics card pretty impressed. NVIDIA held what I thought was a very strong lead with the GTX 680 in March and AMD seemed unwilling to really address it publicly except with a game bundle and modest price drops. NVIDIA’s Kepler architecture was powerful (and power efficient), giving the enthusiast community the impression that the two competitors had swapped positions.

The new Radeon HD 7970 GHz Edition increases clock speeds of the Tahiti GPU by 8-9% and memory speeds by about the same. In general, this results in an increase of 5-12% depending on the game and the resolution being tested. Not only that, but the Catalyst drivers have improved quite a bit since the release of the card in December and January. Games like Skyrim, Batman: Arkham City and DiRT 3 saw improvements of 50%, 20% and 22% respectively on the same hardware with the 12.7 Catalyst beta we used for our testing today. Combine that with the overclocked speeds and you get a performance lead (although very slight) for AMD over NVIDIA’s GTX 680.

I found it pretty interesting how the performance differences played out. NVIDIA’s GTX 680 seemed to win at the lower resolutions of 1680×1050 and 1920×1080 most of the time, but fell behind at 2560×1600 and 5760×1080 regularly. While the added frame buffer on the AMD cards might have helped that, I really think it is just a difference in how the architectures are designed. And even though most gamers are on 1080p or lower resolutions, I would assume that gamers looking to spend ~$500 for a graphics card are planning for bigger screens (or more of them).  

Although I do give the nod to AMD in overall performance, the differences are really quite small and buyers should consider other aspects to that decision.

Power and Efficiency

While the performance win goes to AMD in our opinion, the efficiency, power consumption and architecture "cleanliness" obviously goes to the NVIDIA GeForce GTX 680. The Kepler design is incredible in its ability to deliver awesome performance with minimal power consumption. Although it falls behind the HD 7970 GHz Edition quite a bit, it is able to compete while using approximately 60 watts LESS power. That is a big difference.

But do gamers care enough about that, and the noise and heat dissipation differences that might go along with it – enough to choose the NVIDIA option over the AMD card at the same price point?


Even though the AMD Southern Islands architecture did not really bring any new major features to the fold when it was released last year, AMD still held a big advantage over NVIDIA in many way until the release of Kepler. As it stands now, I would consider NVIDIA in the lead here with cool additions like Adaptive Vsync, frame rate limiting and a great host of monitoring tools for the enthusiast to take advantage of. Yes, AMD does still technically support more displays on a single graphics card, but I think the laws of diminishing returns are quite apparant over the three display mark. 

Pricing and Availability

The new GHz Edition of the Radeon HD 7970 3GB will run you $499. That price is $50 less than the price of the HD 7970 when it first went on sale in January, and right in line with the GTX 680 from NVIDIA that is now in stock throughout the Internet.

Interestingly, all four of these graphics cards have a unique spot in the product stack with this pricing model. The NVIDIA GeForce GTX 680 might start to seem a bit beyond its price when we look at performance alone, but the power efficiency of that card justifies the comparison. The $449 Radeon HD 7970 basic edition will offer performance levels about 10% lower for a 10% price drop, and the GTX 670 makes a strong case at $399. 

AMD says you can expect to see the GHz Edition of the Radeon HD 7970 to be on sale starting late next week.

Final Thoughts

AMD claimed to have the "world’s fastest GPU" during our talk with them about this new graphics card a couple weeks back. While I didn’t believe them at the time, I have to say I agree today. Based on performance levels at high resolutions, the Radeon HD 7970 3GB GHz Edition beats out the reference GeForce GTX 680 2GB from NVIDIA for the crown even if that win is by a nose. While impressive, that isn’t the whole story as NVIDIA’s power efficiency still destroys what AMD can do with Tahiti. Despite being a few percentage points slower in most of our gaming tests, the GTX 680 maintains a competitive stance while using 60 watts (!!) less than this new card from AMD.  

While we love to see new graphics cards released, the truth is the HD 7970 GHz Edition is really just an overclocked stock card with the help of added "boost" technology to get the GPU running smoothly at 1050 MHz. If you purchase a retail standard unit for $50 less, and overclock the card yourself to 1050 MHz core clock and 1500 MHz memory clock, you will essentially have this exact performance.

I hate to not come to a very firm conclusion here with the HD 7970 GHz Edition review like I did with the NVIDIA GeForce GTX 680 article, but there are a few absolutes to be considered. If you want the fastest single-GPU graphics card, then the Radeon HD 7970 GHz Edition is it. If you want a card that is both fast without running away with power consumption, the GTX 680 takes that angle. In terms of unique features and cool technology innovations on the software side, NVIDIA’s team again gets the nod from me.

The GPU world is getting interesting again my friends! 

Please check out our in-studio live review of the Radeon HD 7970 GHz Edition with AMD’s Evan Groenke.

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