AMD Radeon HD 7970 Video Card Review
By Gabriel Torres on December 22, 2011


Introduction

Next month AMD will introduce their latest family of graphics chips, called “Southern Islands,” based on a completely new architecture and supporting the new PCI Express 3.0 protocol. The first model to be released will be the most high-end model, the Radeon HD 7970, codename “Tahiti,” which will cost USD 550. Let’s check its performance.

The Radeon HD 7970 has 2,048 processors (“cores”), works at 925 MHz and accesses its 3 GB of GDDR5 memory at 5.5 GHz through a 384-bit interface, creating a bandwidth of 264 GB/s. This GPU is the first DirectX 11.1, the first PCI Express 3.0, and the first 28 nm product to arrive on the market.

The new architecture used by the “Southern Islands” family, which is called “Graphics Core Next” or simply “GCN,” makes it easier to run regular programs on the GPU compared to AMD’s previous generation of GPUs. Therefore, you should expect to see higher performance on applications that use the GPU for speed-up processing. Of course, we will test this feature in this review.

There are several new features available on the Radeon HD 7970. The first one is called “Power Tune,” which is an automatic overclocking feature similar to Intel’s Turbo Boost, which increases the clock of the graphics chip if there is room in its TDP (Thermal Design Power). This video card can consume up to 250 W, so if the GPU is dissipating, say, 100 W, it knows it can have its clock increased for higher performance. According to AMD, the GPU can increase its clock rate up to 30 percent.

Speaking of oveclocking, according to AMD, the Radeon HD 7970 has a lot of headroom for overclocking; the GPU can easily be set to work at 1 GHz or more and the memory at 6.5 GHz or more.

The second new feature is called “Zero Core,” which completely turns off the GPU and the video card fan when the video monitor is commanded to turn off by the operating system after the computer is idle for a long time. The video card consumption during this stage is only 3 W. According to AMD, the Radeon HD 6970 consumes around 20 W when in long idle mode. This feature also works in CrossFireX mode, completely turning off the extra video cards. The Radeon HD 7970 is expected to consume around 15 W when idle, showing a static image.

Another new feature is an integrated video encoder called VCE (Video Codec Engine), which provides hardware acceleration for encoding H.264 videos. The video decoder, called UVD (Unified Video Decoder), was expanded to include support for hardware-based MPEG4 and DivX decoding.

In the table below, we compare the main specifications of the video cards included in our review. The prices listed below do not include rebates. Prices were researched at Newegg.com on the day we published this review, except for the Radeon HD 7970, which is the price advertised by AMD.

Video Card

Core Clock

Shader Clock

Memory Clock (Effective)

Memory Interface

Memory Transfer Rate

Memory

Shaders

DirectX

Price

Radeon HD 7970

925 MHz

925 MHz

5.5 GHz

384-bit

264 GB/s

3 GB GDDR5

2,048

11.1

USD 550

Radeon HD 6970

880 MHz

880 MHz

5.5 GHz

256-bit

176 GB/s

2 GB GDDR5

1,536

11

USD 350

GeForce GTX 580

772 MHz

1,544 MHz

4,008 MHz

384-bit

192.4 GB/s

1.5 GB GDDR5

512

11

USD 500

NVIDIA offers a 3 GB version of the GeForce GTX 580 between USD 530 and USD 590, which is the true competitor against the Radeon HD 7970. However, we didn’t have one to include in our comparison.

You can compare the specs of these video cards with other video cards by taking a look at our “AMD ATI Chips Comparison Table” and “NVIDIA Chips Comparison Table” tutorials.

Today, only the LGA2011 Core i7 processors (“Sandy Bridge-E”) have a PCI Express 3.0 controller. Therefore, we tested the three video cards using a Core i7-3960X processor on a motherboard based on the Intel X79 chipset. Then we tested the Radeon HD 7970 again with a Core i7-980X processor on a motherboard based on the Intel X58 chipset, to see if the use of a PCI Express 2.0 bus would make any difference in performance.

Now let’s take a complete look at the AMD Radeon HD 7970.

The AMD Radeon HD 7970

Below we have an overall look at the AMD Radeon HD 7970 reference model. It requires one six-pin and one eight-pin auxiliary power connectors.

AMD Radeon HD 7970
click to enlarge
Figure 1: AMD Radeon HD 7970

AMD Radeon HD 7970
click to enlarge
Figure 2: AMD Radeon HD 7970

One of the highlights of this video card is the possibility of connecting up to six video monitors at the same time, which is achieved by using a DisplayPort hub or a DisplayPort monitor that provides daisy-chaining capability. The card provides one DVI-D, one HDMI, and two mini DisplayPort connectors. According to AMD, Radeon HD 7970 video cards will come with a single-link active DisplayPort-to-DVI adapter, so you will have two DVI-D connectors available.

AMD Radeon HD 7970
click to enlarge
Figure 3: Video connectors

The AMD Radeon HD 7970 (Cont’d)

The Radeon HD 7970 uses a new cooler, based on vapor chamber technology, which is similar to the technology used by heatpipes. AMD says you can’t remove the GPU cooler, because the performance won’t be the same after you put the video card back together. That is why we didn’t disassemble this video card. Figure 4 was provided by AMD. According to the manufacturer, the fan is also new, providing higher air flow at a lower speed.

AMD Radeon HD 7970
click to enlarge
Figure 4: Video card cooler

The reviewed video card has two BIOS chips, selectable through a switch. This way you can select between the default configuration or an overclocked configuration, which you created and saved “permanently” to the second BIOS chip.

AMD Radeon HD 7970
click to enlarge
Figure 5: BIOS switch

Before seeing the performance results, let’s recap the main features of this video card.

Main Specifications

The main specifications for the AMD Radeon HD 7970 reference model include:

How We Tested

During our benchmarking sessions, we used the configuration listed below. Between our benchmarking sessions, the only variable was the video card being tested.

Hardware Configuration (PCI Express 3.0 Tests)

Hardware Configuration (PCI Express 2.0 Tests)

Hardware Configuration (Both Platforms)

Software Configuration

Driver Versions

Software Used

Error Margin

We adopted a 3% error margin. Thus, differences below 3% cannot be considered relevant. In other words, products with a performance difference below 3% should be considered as having similar performance.

StarCraft II: Wings of Liberty

StarCraft II: Wings of Liberty is a very popular DirectX 9 game that was released in 2010. Though this game uses an old version of DirectX, the number of textures that can be represented on one screen can push most of the top-end graphics cards to their limits. StarCraft II: Wings of Liberty uses its own physics engine that is bound to the CPU and thus does not benefit from PhysX.

We tested this game at 1920x1200 and 2560x1600. The quality of the game was set to the “extreme” preset. We then used FRAPS to collect the frame rate of a replay on the “Unit Testing” custom map. We used a battle between very large armies to stress the video cards.

AMD Radeon HD 7970

Starcraft II: Wings of Liberty

1920x1200

Difference

Radeon HD 7970 (PCI-E 3.0)

215.886

 

Radeon HD 7970 (PCI-E 2.0)

215.875

0%

Radeon HD 6970

201.412

7%

GeForce GTX 580

182.880

18%

AMD Radeon HD 7970

Starcraft II: Wings of Liberty

2560x1600

Difference

Radeon HD 7970 (PCI-E 3.0)

174.754

 

Radeon HD 7970 (PCI-E 2.0)

173.774

1%

Radeon HD 6970

164.431

6%

GeForce GTX 580

161.883

8%

Far Cry 2

Released in 2008, Far Cry 2 is based on a game engine called Dunia, which is DirectX 10. We used the benchmarking utility that comes with this game at 1920x1200 and 2560x1600, setting overall quality to “ultra high,” maximizing all image quality settings, adjusting anti-aliasing to “8x,” and running the “Ranch Long” demo three times. The results below are expressed in frames per second and are an arithmetic average of the three results collected.

AMD Radeon HD 7970

FarCry 2

1920x1200

Difference

GeForce GTX 580

105.1

13%

Radeon HD 7970 (PCI-E 2.0)

95.5

2%

Radeon HD 7970 (PCI-E 3.0)

93.4

 

Radeon HD 6970

87.7

7%

AMD Radeon HD 7970

FarCry 2

2560x1600

Difference

GeForce GTX 580

70.8

2%

Radeon HD 7970 (PCI-E 3.0)

69.7

 

Radeon HD 7970 (PCI-E 2.0)

68.8

1%

Radeon HD 6970

62.1

12%

Aliens vs. Predator

Aliens vs. Predator is a DirectX 11 game that makes full use of tessellation and advanced shadow rendering. We used the Aliens vs. Predator Benchmark Tool developed by Rebellion. This program reads its configuration from a text file. (Our configuration files can be found here.) We ran this program at 1920x1200 and 2560x1600, with texture set at “very high,” shadows set at “medium,” anisotropic filtering set at “8x,” and anti-aliasing set at “2x.”

AMD Radeon HD 7970

Aliens vs. Predator

1920x1200

Difference

Radeon HD 7970 (PCI-E 3.0)

66.4

 

Radeon HD 7970 (PCI-E 2.0)

66.0

1%

Radeon HD 6970

60.1

10%

GeForce GTX 580

52.4

27%

AMD Radeon HD 7970

Aliens vs. Predator

2560x1600

Difference

Radeon HD 7970 (PCI-E 2.0)

41.2

0%

Radeon HD 7970 (PCI-E 3.0)

41.0

 

Radeon HD 6970

38.2

7%

GeForce GTX 580

32.5

26%

DiRT3

DiRT3 is a DirectX 11 game. We measured performance using this game by running a race and then playing it back using FRAPS. We ran this game at 1920x1200 and 2560x1600 with image quality set to “ultra,” with anti-aliasing set at “8xMSAA.”

AMD Radeon HD 7970

DiRT3

1920x1200

Difference

Radeon HD 7970 (PCI-E 3.0)

77.24

 

Radeon HD 7970 (PCI-E 2.0)

76.87

0%

Radeon HD 6970

71.4

8%

GeForce GTX 580

70.43

10%

AMD Radeon HD 7970

DiRT3

2560x1600

Difference

Radeon HD 7970 (PCI-E 3.0)

55.51

 

Radeon HD 7970 (PCI-E 2.0)

55.24

0%

Radeon HD 6970

50.12

11%

GeForce GTX 580

47.58

17%

Deus Ex: Human Revolution

Deus Ex: Human Revolution is another DirectX 11 game. We used the in-game introduction to measure the number of frames per second, using FRAPS. We ran the introduction in two resolutions, 1920x1200 and 2560x1600, maximizing all image quality settings, configuring anti-aliasing as “MLAA Mode” and anisotropic filtering at “16x.”

AMD Radeon HD 7970

Deus Ex: Human Revolution

1920x1200

Difference

Radeon HD 7970 (PCI-E 3.0)

202.62

 

GeForce GTX 580

201.78

0%

Radeon HD 7970 (PCI-E 2.0)

199.78

1%

Radeon HD 6970

184.13

10%

AMD Radeon HD 7970

Deus Ex: Human Revolution

2560x1600

Difference

Radeon HD 7970 (PCI-E 3.0)

133.080

 

Radeon HD 7970 (PCI-E 2.0)

132.470

0%

GeForce GTX 580

131.477

1%

Radeon HD 6970

121.214

10%

Battlefield 3

Battlefield 3 is the latest installment in the Battlefield franchise released in 2011. It is based on the Frostbite 2 engine, which is DirectX 11. In order to measure performance using this game, we walked our way through the first half of the “Operation Swordbreaker” mission, measuring the number of frames per second using FRAPS. We ran this game at 1920x1200 and 2560x1600, maximizing all image quality settings, configuring anti-aliasing as “4xMSAA” and anisotropic filtering at “16x.”

AMD Radeon HD 7970

Battlefield 3

1920x1200

Difference

Radeon HD 7970 (PCI-E 3.0)

56.743

 

Radeon HD 7970 (PCI-E 2.0)

56.181

1%

Radeon HD 6970

50.773

12%

GeForce GTX 580

50.369

13%

AMD Radeon HD 7970

Battlefield 3

2560x1600

Difference

Radeon HD 7970 (PCI-E 2.0)

42.987

2%

Radeon HD 7970 (PCI-E 3.0)

42.312

 

GeForce GTX 580

38.914

9%

Radeon HD 6970

37.448

13%

3DMark 11 Professional

3DMark 11 Professional measures Shader 5.0 (i.e., DirectX 11) performance. We ran this program at 1920x1200 and 2560x1600, selecting the four graphics tests available and deselecting the other tests available. We used two image quality settings, “performance” and “extreme,” both at their default settings. The results being compared are the “GPU Score” achieved by each video card.

AMD Radeon HD 7970

3DMark 11 - Performance

1920x1200

Difference

Radeon HD 7970 (PCI-E 3.0)

4026

 

Radeon HD 7970 (PCI-E 2.0)

3968

1%

Radeon HD 6970

3724

8%

GeForce GTX 580

3152

28%

AMD Radeon HD 7970

3DMark 11 - Performance

2560x1600

Difference

Radeon HD 7970 (PCI-E 2.0)

2383

1%

Radeon HD 7970 (PCI-E 3.0)

2353

 

Radeon HD 6970

2175

8%

GeForce GTX 580

1846

27%

AMD Radeon HD 7970

3DMark 11 - Extreme

1920x1200

Difference

Radeon HD 7970 (PCI-E 3.0)

2476

 

Radeon HD 7970 (PCI-E 2.0)

2439

2%

Radeon HD 6970

2144

15%

GeForce GTX 580

1892

31%

AMD Radeon HD 7970

3DMark 11 - Extreme

2560x1600

Difference

Radeon HD 7970 (PCI-E 3.0)

1537

 

Radeon HD 7970 (PCI-E 2.0)

1519

1%

Radeon HD 6970

1302

18%

GeForce GTX 580

1153

33%

Media Espresso 6.5

Media Espresso is a video conversion program that uses the graphics processing unit of the video card to speed up the conversion process. We converted a 449 MB, 1920x1080i, 18,884 kbps, MPEG2 video file to a smaller 640x360, H.264, .MPG4 file for viewing on a portable device such as an iPhone or iPod Touch. We also ran this test on our two CPUs (Core i7-980X and Core i7-3960X) in order to compare the difference in performance of using a high-end CPU and a high-end GPU to transcode video.

AMD Radeon HD 7970

Media Espresso 6.5

Seconds

Difference

Radeon HD 7970 (PCI-E 3.0)

29

 

Radeon HD 7970 (PCI-E 2.0)

36

19%

GeForce GTX 580

44

34%

Core i7-3960X

46

37%

Radeon HD 6970

48

40%

Core i7-980X

65

55%

Conclusions

The Radeon HD 7970 proved to be the fastest single-GPU video card ever released. It was between 8% and 33% faster than the GeForce GTX 580 in most games we ran. The exceptions were Deus Ex: Human Revolution, where both video cards achieved the same performance level, and Far Cry 2, where the NVIDIA video card was 13% faster at 1920x1200, with both achieving the same performance level at 2560x1600.

Using the video card for video encoding with Media Espresso 6.5, we saw the Radeon HD 7970 running 52% faster than the GeForce GTX 580, 59% faster than a Core i7-3960X CPU (which is the fastest desktop CPU available on the market today), and 124% faster than a Core i7-980X, making it a terrific video card for accelerating processing using the GPGPU technique.

In this review, we could answer one of the most common questions about this new video card: Will I lose performance if I install it on a PCI Express 2.0 system? The answer is no. In our test, we saw no performance difference between running this video card on a PCI Express 3.0 system and running it on a PCI Express 2.0 system, as current games are not saturating the bandwidth provided by the PCI Express 2.0 connection. This is really good news for users who don’t want to sell a kidney to buy a new system based on a “Sandy Bridge-E” processor. However, we saw a significant 24% performance difference between PCI Express 3.0 and 2.0 when running Media Espresso. This means that for using the video card to process general computing tasks, it is better to have the PCI Express 3.0 platform.

The only problem with this video card is, of course, its price. It is better than the GeForce GTX 580, but that doesn’t mean that the average user can afford it. If money isn’t an issue, buy the new Radeon HD 7970 and be happy!

Originally at http://www.hardwaresecrets.com/article/AMD-Radeon-HD-7970-Video-Card-Review/1458


© 2004-13, Hardware Secrets, LLC. All Rights Reserved.

Total or partial reproduction of the contents of this site, as well as that of the texts available for downloading, be this in the electronic media, in print, or any other form of distribution, is expressly forbidden. Those who do not comply with these copyright laws will be indicted and punished according to the International Copyrights Law.

We do not take responsibility for material damage of any kind caused by the use of information contained in Hardware Secrets.