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AMD Radeon HD 7870 and 7850 GPU Previews
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Date: Mar 05, 2012
Section:Graphics/Sound
Author: Marco Chiappetta
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Introduction and Specifications

Here we are, less than three weeks removed from the launch of the Radeon HD 7700 series, and AMD is already at it again. Today we’ll be showing you the first two members of the Radeon HD 7800 series of graphics cards, the Radeon HD 7870 GHz Edition and Radeon HD 7850. These two graphics cards are based on yet another new GPU design, which features AMD’s Graphics Core Next architecture, or GCN. Whereas the high-end Radeon HD 7900 series cards feature AMD’s Tahiti GPU and the more mainstream Radeon HD 7700 series is based on the company’s Cape Verde GPU, the new Radeon HD 7800 series is built around a GPU codenamed Pitcairn.

Although all of the members of the Radeon HD 7000 series are based on GPUs in AMD’s “Southern Islands” family of graphics processors, the three GPUs in the family target very different market segments. Cape Verde targets mainstream users, while Tahiti caters to ultra-enthusiasts who like to remain on the bleeding edge. Pitcairn, however, is targeted at the traditional sweet spot of the market, somewhere in the mid-range, between high-end and entry-level type products.


AMD Radeon HD 7870 GHz Edition and Radeon HD 7850 DirectX 11 Graphics Cards

AMD Radeon HD 7870 and 7850
Specifications & Features


The main features and specifications of the Radeon HD 7870 GHz Edition and Radeon HD 7850 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 7800 series fits in AMD’s current graphics card line-up.


The "Southern Islands" Family of AMD GPUs

Before we dig into the specifics, 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 Pitcairn GPU is based on the same graphics architecture as AMD’s previously-released high-end products, we’ve covered many of its key features at length already. As such, we won’t be diving in to some of them again here.

In our coverage of the 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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Pitcairn GPU, New Features

As we’ve mentioned, the Pitcairn GPU powering the Radeon HD 7800 series cards is based on the Graphics Core Next (GCN) architecture and has essentially the same feature set as its higher-end counterpart (Tahiti) found on the Radeon HD 7900 series.


Pitcairn GPU Specifics

Like Tahiti and the mainstream Cape Verde GPUs, Pitcairn is manufactured using TSMC’s advanced 28nm process node. The Pitcairn GPU, however, is comprised of roughly 2.8B transistors and outfitted with a maximum of 1,280 stream processors (to Tahiti’s 2,048) arranged in 20 compute units with 64 stream processors each. Pitcairn also sports dual Geometry engines, 32 ROPs, 80 texture units, and a 256-bit GDDR5 memory interface; double-up on Cape Verde and you've basically got Pitcairn. According to AMD, the die size of the chip is a relatively small 212 square millimeters (Tahiti is 365mm2, Cape Verde is 123mm2).

Although the Pitcairn GPU powering the Radeon HD 7800 series is pared down somewhat to hit more affordable price points, it doesn’t skimp on any features. With fewer stream processors, ROPs, and texture units, and a narrower memory interface, Pitcairn's performance will be lower than Tahiti, but its feature set remains unchanged.


Sparse Grid Supersample Anti-Aliasing
 

Morhpological AA 2.0 (MLAA 2.0)

While we're talking about features, we should also mention a couple of new feature additions coming with AMD's Catalyst 12.3 beta and 12.4 WHQL drivers. When those drivers hit, Radeon HD 6000 and 7000 series owners will have access to two new anti-aliasing modes. MLAA 2.0 (Morphological AA) uses an enhanced algorithm that offers better performance and image quality than the original. A new Sparse Grid Supersample AA mode will also be made available that works with DirectX 9, 10, and 11 titles. This SSAA mode will be further updated when the Catalyst 12.3 (and newer) drivers arrive, with automatic LOD adjustments to maintain sharper textures.
 

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Radeon HD 7870 and 7850
The card you see pictured directly below is the Radeon HD 7870 GHz Edition. The Radeon HD 7870 is outfitted with a fully functional Pitcairn GPU with all of its CUs and texture units intact and enabled.

  



  
AMD Radeon HD 7870 GHz Edition

As the full name of this card suggests, the Radeon HD 7870 GHz Edition’s GPU is clocked at a cool 1GHz—a second for a reference GPU from AMD (the Radeon HD 7770 was the first). With a 1GHz Pitcairn GPU paired to 2GB of GDDR5 memory clocked at 1.20GHz (4.8Gbps data rate), the Radeon HD 7870 offers up 2.56 TFLOPS of compute performance, with a texture fillrate of 80GT/s, a pixel fillrate of 32 GP/s, and peak memory bandwidth of 153.6 GB/s.

The Radeon HD 7870 GHz Edition card is outfitted with a dual-slot cooler, but has a relatively modest (in light of higher-end cards) 9.5” PCB. With a 175W TDP, the Radeon HD 7870 requires a pair of 6-pin PCI Express power feeds, and its outputs consist of a single HDMI output, two mini-DisplayPort 1.2 outputs, and one Dual-Link DVI output.

  



  
AMD Radeon HD 7850

The Radeon HD 7850 has the same output configuration as the Radeon HD 7870, but its Pitcairn GPU is pared down somewhat. The GPU at the heart of the Radeon HD 7850 has four of its compute units disabled, so “only” 1,024 stream processors and 64 texture units are enabled. The GPU is also clocked lower at 860MHz. The Radeon HD 7850’s differences result in 1.76 TFLOPS of compute performance, with peak texture and pixel fillrates of 55 GT/s and 27.52 GP/s, respectively. The card’s memory, however, is clocked at the same 1.2GHz as the Radeon HD 7870, so memory bandwidth remains unchanged at 153.6 GB/s.

With its pared-down, lower clocked, GPU, the Radeon HD 7850 requires less power than the Radeon HD 7870—130w vs. 175w. As such, the Radeon HD 7850 can get by with only one additional 6-pin power feed (75w is supplied by the slot, 75w by the additional 6-pin feed). The reference Radeon HD 7850 we received for testing has the same 9.5” PCB and dual-slot cooler design as the 7870, but some non-reference cards due to hit retail shelves will sport shorter, 8.25" PCBs.
 
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Test System and Unigine Heaven v2.5

How We Configured Our Test Systems: We tested the graphics cards in this article on an Asus P9X79 Deluxe motherboard powered by a Core i7-3960X six-core processor and 16GB of G.SKILL DDR3-1600 RAM. The first thing we did when configuring the test system was enter the system UEFI and set all values to their "optimized" or "high performance" default settings and disabled any integrated peripherals that wouldn't be put to use. The hard drive was then formatted and Windows 7 Ultimate x64 was installed. When the installation was complete we fully updated the OS and installed the latest DirectX redist, along with the necessary drivers, games, and benchmark applications.

HotHardware's Test System
Intel Core i7 Powered

Hardware Used:
Intel Core i7-3960X
(3.3GHz, Six-Core)
Asus P9X79 Deluxe
(Intel X79 Express)

Radeon HD 7870
Radeon HD 7850
Radeon HD 7950
Radeon HD 7970
Radeon HD 6870
Radeon HD 6970
Radeon HD 6970
GeForce GTX 580
GeForce GTX 570
GeForce GTX 560 Ti

16GB OCZ DDR3-1600
Western Digital Raptor 150GB
Integrated Audio
Integrated Network

Relevant Software:
Windows 7 Ultimate x64
DirectX April 2011 Redist
ATI Catalyst v12.2b
NVIDIA GeForce Drivers 295.73

Benchmarks Used:

Unigine Heaven v2.5
3DMark 11
Batman: Arkham City
Just Cause 2
Alien vs. Predator
Metro 2033
Lost Planet 2
Dirt 3

Unigine Heaven v2.5 Benchmark
Pseudo-DirectX 11 Gaming


Unigine Heaven

Unigine's Heaven Benchmark v2.5 is built around the Unigine game engine. Unigine is a cross-platform, real-time 3D engine, with support for DirectX 9, DirectX 10, DirectX 11 and OpenGL. The Heaven benchmark--when run in DX11 mode--also makes comprehensive use of tessellation technology and advanced SSAO (screen-space ambient occlusion) It also features volumetric cumulonimbus clouds generated by a physically accurate algorithm and a dynamic sky with light scattering.

The new Radeon HD 7800 series cards performed well in the tessellation-heavy Unigine Heaven benchmark. In this test, the Radeon HD 7870 was able to squeak past the GeForce GTX 570, while the Radeon HD 7850 landed right in between the GeForce GTX 560 Ti and GTX 570. Both of the 7800 series cards, however, had no trouble besting any of the 6900/6800-series Radeons.

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3DMark 11 Performance

Futuremark 3DMark11
Synthetic DirectX Gaming


Futuremark 3DMark11

The latest version of Futuremark's synthetic 3D gaming benchmark, 3DMark11, is specifically bound to Windows Vista and WIndows 7-based systems due to its DirectX 11 requirement, which isn't available on previous versions of Windows. 3DMark11 isn't simply a port of 3DMark Vantage to DirectX 11, though. With this latest version of the benchmark, Futuremark has incorporated four new graphics tests, a physics tests, and a new combined test. We tested the graphics cards here with 3DMark11's Extreme preset option, which uses a resolution of 1920x1080 with 4x anti-aliasing and 16x anisotropic filtering.

3DMark 11 tells a different story than the Heaven benchmark on the previous page. Versus the GeForce GTX 570 and GTX 560 Ti, the new Radeon HD 7800 series cards stack up similarly, with the 7870 besting the GTX 570 and the 7850 edging out the GTX 560 Ti. The Radeon HD 6970, however, was able to overtake the Radeon HD 7850 here.
 

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Just Cause 2 Performance

Just Cause 2
DX10.1 Gaming Performance


Just Cause 2

Just Cause 2 was released in March '10, from developers Avalanche Studios and Eidos Interactive. The game makes use of the Avalanche Engine 2.0, an updated version of the similarly named original. It is set on the fictional island of Panau in southeast Asia, and you play the role of Rico Rodriquez. We benchmarked the graphics cards in this article using one of the built-in demo runs called Desert Sunrise. The test results shown here were run at various resolutions and settings. This game also supports a few CUDA-enabled features, but they were left disabled to keep the playing field level.

It was a photo finish between the GeForce GTX 570 / 560 Ti and Radeon HD 7870 / 7850 in the Just Cause 2 benchmark. In this test, the Radeon HD 7870 just barely beat the GeForce GTX 570 at the higher, more-taxing resolution, while the Radeon HD 7850 finished ever so slightly ahead of the GeForce GTX 560 Ti at both resolutions. The 7800-series cards, once again, outpaces the Radeon HD 6900 and 6800 series cards.
 

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Lost Planet 2 Performance

Lost Planet 2
DirectX 11 Gaming Performance


Lost Planet 2

A follow-up to Capcom’s Lost Planet : Extreme Condition, Lost Planet 2 is a third person shooter that takes place again on E.D.N. III ten years after the story line of the first title. We ran the game’s DX11 mode which makes heavy use of DX11 Tessellation and Displacement mapping and soft shadows. There are also areas of the game that make use of DX11 DirectCompute for things like wave simulation in areas with water. This is one game engine that looks significantly different in DX11 mode when you compare certain environmental elements and character rendering in its DX9 mode versus DX11. We used the Test B option built into the benchmark tool and with all graphics options set to their High Quality values.

Like Unigine Heaving, The Lost Planet 2 benchmark makes heavy use of tessellation. In this benchmark, the GeForce GTX 570 is able to pull ahead of the Radeon HD 7870, but the Radeon HD 7850 trades victories with the GeForce GTX 560 Ti. Versus the older 6900 series cards, the Radeon HD 7870 has no trouble pulling ahead, but the Radeon HD 7850 performs right about on par with, or perhaps slightly better, than the Radeon HD 6970.
 

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Metro 2033 Performance

Metro 2033
DirecX11 Gaming Performance


Metro 2033

Metro 2033 is your basic post-apocalyptic first person shooter game with a few rather unconventional twists. Unlike most FPS titles, there is no health meter to measure your level of ailment, but rather you’re left to deal with life, or lack there-of more akin to the real world with blood spatter on your visor and your heart rate and respiration level as indicators. The game is loosely based on a novel by Russian Author Dmitry Glukhovsky. Metro 2003 boasts some of the best 3D visuals on the PC platform currently including a DX11 rendering mode that makes use of advanced depth of field effects and character model tessellation for increased realism. This title also supports NVIDIA PhysX technology for impressive in-game physics effects. We tested the game resolutions of 1920x1200 and 2560x1600 with adaptive anti-aliasing and in-game image quality options set to their High Quality mode, with DOF effects disabled.

The new Radeon HD 7800 series cards performed fairly well in the Metro 2033 benchmark. In this test, the Radeon HD 7870 outpaced the GeForce GTX 570 and all of the 6900 and 6800-series Radeons, while the Radeon HD 7850 finished about 10% faster than the GeForce GTX 560 Ti and nipped at the GTX 570's heels.
 

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Batman: Arkham City Performance

Batman: Arkham City
DirectX Gaming Performance


Batman: Arkham City

Batman: Arkham City is a sequel to 2009’s Game of the Year winning Batman: Arkham Asylum. This recently released sequel, however, lives up to and even surpasses the original. The story takes place 18 months after the original game. Quincy Sharp, the onetime administrator of Arkham Asylum, has become mayor and convinced Gotham to create "Arkham City" by walling off the worst, most crime-ridden areas of the city and turning the area into a giant open-air prison. The game has DirectX 9 and 11 rendering paths, with support for tessellation, multi-view soft shadows, and ambient occlusion. We tested in DX11 mode with all in-game graphical options set to their maximum values, at various resolutions.

The Radeon HD 7870 offered identical performance to the Raedon HD 6970 in the Batman: Arkham City benchmark, and significantly trailed the GeForce GTX 570. The Radeon HD 7850, however, was significantly faster than the GeForce GTX 560 Ti and Radeon HD 6950.
 

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Dirt 3 Performance

Dirt 3
DirectX 11 Gaming Performance


Dirt 3

Dirt 3 is the latest in a string of great racing games from Codemasters. Like is predecessor, 2009's Dirt 2, this game sports impressive visuals with DX11 support. “Ultra” settings for shadow effects, tessellation, and post processing elements, like depth of field, then become available to the gamer, and in turn, crank up the workload on the graphics subsystem. The game engine also makes use of multi-core processors for higher performance on top-end systems. We tested the game configured with its Ultra graphics options with 4X anti-aliasing at resolutions with of 1920x1200 and 2560x1600.

Dirt 3 proved to be somewhat of a weak point for the Radeon HD 7800 series cards. The Radeon HD 7870 trailed the GeForce GTX 570 here, while the Radeon HD 7850 trailed the GeForce GTX 560 Ti.
 

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Alien vs. Predator Performance

Alien vs. Predator
DirectX 11 Gaming Performance


Alien vs. Predator

The Alien vs. Predator benchmark makes use of the advanced Tessellation, screen space ambient occlusion and high-quality shadow features, available with DirectX 11. In addition to enabling all of the aforementioned DirectX 11 related features offered by this benchmark, we also switched on 4X anti-aliasing along with 16X anisotropic filtering to more heavily tax the graphics cards being tested.

The trend that we've seen in the majority of tests to this point, played out again in the Alien vs. Predator benchmark. In this test, the Radeon HD 7870 outpaced the GeForce GTX 570 and the Radeon HD 7850 pulled ahead of the GeForce GTX 560 Ti.
 

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Power Consumption, Noise, Temps

Before bringing this article to a close, we'd like to cover a few final data points--namely power consumption and noise. Throughout all of our benchmarking and testing, we monitored acoustics and tracked how much power our test system was consuming using a power meter. Our goal was to give you an idea as to how much power each configuration used while idling and while under a heavy workload. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power drawn by the graphics cards alone.

Total System Power Consumption
Tested at the Outlet

The new Radeon HD 7800 series cards proved to be fairly power friendly. While idling, they were among the lowest offenders, and the same held true while under load. Despite offering much better performance than the Radeon HD 6870, the Radeon HD 7850 consumed less power under load. And the Radeon HD 7870 consumed significantly less power than the GeForce GTX 570 or Radeon HD 6970, while offering similar or better performance.

With their manageable power consumption characteristics, temperatures and noise were non-issues with the Radeon HD 7800 series cards. We saw some weirdness where the GPU fans on the cards would spin up while powering-up or rebooting our testing system, but once the drivers initialized in Windows, the cards were mostly silent. While idling temperatures on both cards remained in the mid-to-upper 30 degree celcius range, with fans spinning at, or around, 20%. Under load while gaming, we saw a peak temperature on the higher-clocked 7870 of only about 69'C, with a fan speed that hovered in the 30%-33% range, which was audible, but quiet in our opinion.
 

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Our Summary and Conclusion

Performance Summary: Summarizing the Radeon HD 7800 series performance is fairly easy. Throughout our entire battery of benchmarks, the Radeon HD 7870 GHz Edition typically outpaced the Radeon HD 6970 and GeForce GTX 570 by a few percentage points, although there were a few cases where the previous-gen cards were able to pull ahead. The Radeon HD 7850 was generally able to outpace the Radeon HD 6950 and GeForce GTX 560 Ti as well, though again, there were instances where the previous-gen cards had a slight advantage like in AvP or Dirt 3. In newer titles that make use of tessellation and other DX11 features, the Radeon HD 7800 series usually fared better, but overall, performance was very good across the board.


The AMD Radeon HD 7870 GHz Edition and Radeno HD 7850 Reference Cards.

The Radeon HD 7800 series is meant to supplant the Radeon HD 6900 series in AMD’s graphics card line-up. Looking back at the numbers, it seems AMD has executed well on that plan, as the newer Radeon HD 7800 series cards offered similar or better performance than their Radeon HD 6900 series counterparts, but with more features, markedly lower power characteristics and better acoustic profiles.

If you can find Radeon HD 6970 and 6950 cards in stock, they’re currently selling for approximately $340-400 (6970) and $250-$300 (6950). As has been the case with the entire Radeon HD 7000 series thus far, AMD has priced the new Radeon HD 7870 GHz Edition and Radeon HD 7850 right where they “can” be priced. The suggested e-tail price for the AMD Radeon HD 7870 GHz Edition will start at $349 and the Radeon HD 7850 will start at $249, when they begin volume shipments on March 19. Considering the new cards have more features, are faster, quieter, and more power-friendly, those prices are easily justifiable. But as we’ve said in the last few AMD graphics card launches, we wish the company was more aggressive with regard to pricing this time around. GeForce GTX 570 cards, for example, can already be found for around $330 and GTX 560 Ti cards for about $230, so NVIDIA doesn’t really need to react with price drops on their competing current offerings. We get the feeling AMD is pricing these cards where they can, at least until NVIDIA officially shows their hand with their next-gen Kepler-based parts. Hopefully, we’ll have some news we can share with you on that front in the not too distant future.

Regardless, AMD has been on tear with GPU launches and despite their less-than-aggressive pricing, the Radeon HD 7800 series appears solid. The cards performed well and they ran relatively cool and quiet. If you’re in the market for a graphics card in their price range, the Radeon HD 7800 series deserves to be on your short list.

  • Good Performance
  • Relatively Low Power Consumption
  • Quiet
  • Cutting Edge Features
  • Won't Be Available For A Couple of Weeks
  • Not Much Faster Than Previous Gen Counterparts



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