AMD Radeon HD 7970 GHz Edition Review - HotHardware

AMD Radeon HD 7970 GHz Edition Review

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It was exactly 6 months ago to the minute that AMD officially took the wraps off its Tahiti GPU and the original Radeon HD 7970. The Radeon HD 7970 was the first graphics card to feature AMD’s “Graphics Core Next”, or GCN, architecture and when it hit the scene, the Radeon HD 7970 proved to be the fastest single-GPU based graphics card available.

Since that time though, NVIDIA went ahead and released their Kepler-based GK104 GPU and the GeForce GTX 600 series of graphics cards. Although GK104 was comprised of fewer transistors and used less power, it ended up outpacing the Radeon HD 7970 more often than not, and propelled NVIDIA back into a leadership position at the high-end of the graphics card market.

As you can imagine, that didn’t sit well with AMD. So, for Tahiti’s half-birthday, they went ahead and refreshed the Radeon HD 7970, by tweaking a few key aspects of the card and adding some new features. The end result is the Radeon HD 7970 GHz Edition, an update to the original with a faster GPU, higher-clocked memory, and a new PowerTune with Boost feature that dynamically adjusts the GPU frequency and voltage when headroom is available.

AMD says the Radeon HD 7970 GHz Edition is the “World’s fastest and most versatile GPU”. Are they correct? Let’s fire the thing up and find out...

The AMD Radeon HD 7970 GHz Edition 3GB Graphics Card

AMD Radeon HD 7970
Specifications & Features

Processing Units
Stream Processors 2048
Compute Performance (SPDP/DPFP) 4.3 TFLOPS / 1.08 TFLOPS
Texture Units 128
Z/Stencil 128
ROP Units 32
Clock Speeds
Engine Clock 1000 MHz
Boost Clock 1050 MHz
Memory Clock (Data Rate) 6.0Gbps / 6 GHz (effective)
Memory Type GDDR5
Total Video Memory 3072MB
Memory Interface 384-bit
Total Memory Bandwidth 288 GB/s
Texture Filtering Rate (Bilinear) 134.4 GT/sec [33.6 GP/sec]
Physical & Thermal
Fabrication Process 28 nm
Transistor Count 2.8 Billion
Connectors 1 x Dual-Link DVI, 2 x mini-DP, 1 x HDMI
Form Factor Dual Slot
Power Connectors 1 x 6-pin, 1 x 8-pin
Recommended Power Supply 500 watts
Thermal Design Power (TDP) ~250 watts
AMD ZeroCore Power <2 watts

The main features and specifications of the Radeon HD 7970 GHz Edition are outlined in the chart above. We’ll go more in-depth on the coming pages, but for now, the information above should give you all an idea as to where the Radeon HD 7970 GHz Edition fits in AMD’s current graphics card line-up. Hint: It's the fastest single-GPU powered card from AMD to date.

Tahiti is turning .5 years old today!

Before we dig into the specifics of the Radeon HD 7970 GHz Edition, however, we’d like to direct you attention to a few recent articles that will help lay the foundation for what we’ll be showing you on the pages ahead. Since the Tahiti GPU at the heart of the card is identical to one use on AMD’s previously-released, high-end Radeon HD 7900 series products, we’ve covered many of its key features at length already. As such, we won’t be diving in to them again here.

In our coverage of the original Radeon HD 7970 launch, we detail all of the key features of AMD’s Graphics Core Next (GCN) architecture and discuss features like PowerTune and AMD ZeroCore Power technology, GCN Tessellation, Partially Resident Textures (PRT), and Discrete Digital Multi-Point audio, among others. In our Radeon HD 7950 coverage, we’ve got CrossFireX scores with the 7900-series and in the Radeon HD 7770 and 7750 launch piece, we detail AMD’s latest mainstream DX11 offerings and discuss how GCN was scaled down to cater to different market segments.

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Nice card. I'd like to try one out.

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Marco, when this card was tested by the Sweclockers team ( - in Swedish), the conclusions reached were much the same as those you list in your summary above. However, a couple of additional things were noted - the so-called «PowerTune Technology» didn't really work as expected ; instead of the card being tested (much the same line up as in your HH test) running at the basic 1000 MHz speed and being «dynamically» boosted to 1050MHz when required, throughout the whole test the card ran consistently at 1050 MHz, save for a dip to around 1020MHz for perhaps a tenth of a second on a single occasion. Moreover, available software does not permit card voltage to be increased over the standard 1.2V (which itself is a minor increase over the standard 1.175V of the standard 7970), which, of course, limits the card's overclocking potential. Thus, according to the Sweclockers reviewers, the HD 7970 GHz amounts to a factory overclocked HD 7970, in which the engine clock has been boosted to 1050MHz from 925MHz, the memory clock to 6GHz from 5.5GHz, and voltage, as noted above, to 1.2V from 1.175V. An owner of a HD 7970 card should therefore be able to attain the same performance levels as the HD 7970 GHz card by means of a relative modest overclocking of his or her card. In other words, the HD 7970 GHz card, while it does take the speed crown from the GeForce GTX 680 (on most applications), doesn't represent anything new....

Love to hear your comments on the above !...


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Well, it's the same GPU and PCB, and as I stated the only changes to the card are on the firmware level, so technically the 7970 GHz Edition is just an overclocked 7970. If you'v got (or anyone's got) a 7970 that'll overclock to the same levels, performance will be identical.

AMD also showed me (and a handful of other tech journalists) the card in action a couple weeks back at the AFDS, and the Boost frequency was fluctuating up and down. It's not as granular as NVIDIA's implementation, but it does work.  I'm not sure what that other site used to monitor frequencies, but Overdrive just reports the "high-performance" clock. Not sure GPU-Z reads frequencies properly either, but don't quote me on that one...I'm not certain.

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Thanks, Marco, for your reply ! The two Sweclockers testers, Jonas Thörnqvist and Emil Björklund, state the following in an explanatory video that they felt compelled to add to the summary section of their detailed, multi-page review (2:59 - 3:17 into the video) : «... the drivers report a clock frequency of 1050MHz, GPU-Z reports a clock frequency of 1050MHz (this could, per se, be due to the software's lack of support for the Turbo fuction), but the point is that, no matter how much one looks at the card, it always runs at 1050MHz ...»

In any event, thanks for an excellent review !...


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So, they're wrong in their assessment. GPU-Z detects the card properly, but doesn't poll clocks correctly yet. The Boost frequency definitely fluctuates. I saw it in action with my own eyes. The tool AMD was using to demo Boost, however, wasn't public. I was the functionality may be incorporated into a future release of the Catalyst Control Center.

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Don't worry, the 12.11 catalyst drivers will resolve alot of issues these cards have been having and will also increase performance by 5%-20%. Once these drivers are released the ATi cards will be faster than their Nvidia competitors along the same model comparison.

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