When AMD released the Radeon HD 2900 XT in May of last year, we were left with a bitter taste in our mouths.  Not because the product was all that bad, but because it seemed AMD was content to leave NVIDIA uncontested at the high-end of the 3D graphics card market.  If you remember, when the Radeon HD 2900 XT launched AMD had targeted the mid-range GeForce 8800 GTS, and not NVIDIA’s high-end 8800 GTX or Ultra.  It seemed as if AMD just didn’t want to be in the fight for 3D graphics supremacy any longer and enthusiasts like yourselves, who seek nothing but the highest performing products, were left with only a single option.

Thankfully things have changed in the last few months.  After the R600 shipped, AMD’s engineers went right back to work.  And in November AMD released the Radeon HD 3800 series of products, which were based on an updated GPU design that performed much like the R600, but with more moderate power and thermal characteristics.  The new GPU, formerly codenamed RV670, still wasn’t quite as fast as NVIDIA’s higher-end offerings, but its low power profile gave AMD the ability to engineer the product we’ll be showcasing here today, the Radeon HD 3870 X2.

The Radeon HD 3870 X2 was codenamed R680 throughout its development.  Although that codename implies the card is powered by a new GPU, it is not.  The Radeon HD 3870 X2 is instead powered by a pair of RV670 GPUs linked together on a single PCB by a PCI Express fan-out switch.  In essence, the Radeon HD 3870 X2 is “CrossFire on a card”.  Take a look...

ATI Radeon HD 3870 X2

To get more familiar with AMD's new ATI Radeon HD 3870 X2, the company's previous GPU architectures, and their key features, we recommend you read a few recent articles we've posted here at HotHardware. The Radeon HD 3870 X2's pair of RV670 GPUs are derived from of the R600, and as such they have a number of key features in common that we've already covered in much greater detail that we will here today. The articles we suggest you check out include:

• ATI Radeon HD 3870 / 3850
• ATI Radeon HD 2900 XT: The R600 Has Arrived
• Radeon X1950 Pro with Native CrossFire
• ATI Crossfire Multi-GPU Technology Preview

If you haven't already done so, we recommend scanning through our Radeon HD 3800 and 2900 series coverage, our CrossFire Multi-GPU technology preview, and the Radeon X1950 Pro with Native CrossFire article. In those four pieces, we cover a large number of the features offered by the new Radeon HD 3870 X2 and explain many of the features of DirectX 10 and 10.1. We recommended reading these articles because there is quite a bit of background information in them that'll make it easier to fully digest what we're going to showcase here today.

At first glance, the Radeon HD 3870 X2 looks much like AMD’s previous high-end GPU offerings.  The card features ATI’s signature red PCB with an up-close-and-personal look into Ruby’s eyes emblazoned on the fan shroud.  Flip the card over, however, and it becomes abundantly clear that the Radeon HD 3870 X2 has a lot going on under its cooler.

     


    


    
AMD's Reference ATI Radeon HD 3870 X2 Card

 
As we’ve already mentioned, the Radeon HD 3870 X2 is powered by a pair of RV670 GPUs, the same chips used on the Radeon HD 3870 and 3850.  The two GPUs are linked together on the PCB through a PCI Express fan-out switch from PLX.  That switch takes the 16 PCI express lanes coming from the PEG slot and distributes them to both of the GPUs.  We should note, however, that although the RV670 GPU has a native PCI Express 2.0 interface, the on-board switch is PCI Express 1.1 compliant only.  Also note that the 3870 X2 has only a single CrossFire edge connector along the top of its PCB.  It has only one because the other connection is already utilized on the PCB.  Although the Radeon HD 3870 X2 is equipped with a CrossFire connector, at this time drivers are not available that will allow end users to link two of these cards together for quad-GPU CrossFireX.  Those drivers are coming though.

Each of the GPUs on the Radeon HD 3870 X2 has its own 512MB frame buffer, for a total of 1GB of on-board memory.  As you can see, the entire assembly is quite large and results in a 10.5” PCB – a little longer than a standard ATX motherboard.  The cooler used on the card is much like previous offerings, but there are some noteworthy elements to the design.  Each of the GPUs gets its own all copper heatsink, but the surrounding heatplate and heatsinks for the switch and RAM is made of aluminum.  AMD went with a hybrid aluminum and copper cooler to keep the card’s weight down, but it is still quite heavy.

Like the other members of the Radeon HD 3800 series, AMD’s reference ATI Radeon HD 3870 X2 has a pair of dual-link DVI outputs, and an HD video output.  One of the DVI outputs can be converted to an HDMI output with audio using an included adapter.  Because the Radeon HD 3870 X2 has dual GPUs though, it is capable of supporting four DVI outputs.
 

If you look at the breakdown above, the Radeon HD 3870 X2 isn’t simply two Radeon HD 3870s fused together on a single PCB.  The GPUs on the Radeon HD 3870 X2 will be clocked at a minimum of 825MHz, up from the standard 3870’s 775MHz.  The X2’s frame buffer memory will be clocked lower, however, 1.8GHz vs. 2.25GHz.  What this means is that in applications that are limited by shader performance and fillrate, the X2 should be faster than a pair of Radeon HD 3870 cards running in CrossFire mode.  Conversely, in applications that are memory bandwidth bound, the dual-card CrossFire configuration should be somewhat faster.

In the days leading up to this launch, we were contacted by a number of ATI’s board partners and given information regarding their Radeon HD 3870 X2 offerings.  The cards pictured below come from Asus and HIS.

    
Asus Has Two Radeon HD 3870 X2 Cards In The Works
 

We received word of two Radeon HD 3870 X2 cards Asus plans to release.  One model is essentially a copy of ATI’s reference design with the same clock speeds and 1GB frame buffer.  But Asus claims their card will ship with highly-overclockable .8ns RAM.  The other Asus-made X2 features a custom cooler design and quad DVI outputs.  Although the Radeon HD 3870 X2 is clearly designed for gamers, we can see Asus getting some attention from investment professionals and CAD workstation types that regularly use multi-monitor setups.  We should also point out that both of Asus’ offerings will include a copy of the DX10 game Company of Heroes: Opposing Fronts.  You can expect full reviews of these cards in the near future.

     


     
The HIS Radeon HD 3870 X2
 

The HIS Radeon HD 3870 X2 is also based on ATI’s reference design, sans the large decal on the fan shroud.  With this setup, it’s easy to see the dual-copper heatsinks affixed to the GPUs and the aluminum heatsinks fins in the center that covers the on-board PCI Express fan-out switch.

HIS includes a couple of noteworthy accessories with their Radeon HD 3870 X2 card.  Along with a DVI to HDMI adapter, dual DVI to VGA adapters, a CrossFire bridge connector, and HD component output dongle, the card ships with a driver CD, a case badge, and a certificate for Valve’s Black Box gaming bundle, which is comprised of Half Life: Episode 2, Portal, and Team Fortress 2.  Also included is a handy pen-screwdriver branded with a large HIS logo.

HOW WE CONFIGURED THE TEST SYSTEMS: We tested all of the graphics cards used in this article on either an EVGA nForce 680i SLI motherboard (NVIDIA GPUs) or an Asus P5E3 Deluxe (ATI GPUs) powered by a Core 2 Extreme QX6850 quad-core processor and 2GB of low-latency Corsair RAM. The first thing we did when configuring the test systems was enter their respective BIOSes and set all values to their "optimized" or "performance" default settings. Then we manually configured the memory timings and disabled any integrated peripherals that wouldn't be put to use. The hard drive was then formatted, and Windows Vista Ultimate was installed. When the installation was complete we fully updated the OS, and installed the latest DX10 redist and various hotfixes along with the necessary drivers and applications.
  

The HotHardware Test System Core 2 Extreme Powered

Processor - Motherboard - Video Cards - Memory - Audio - Hard Drive -

Hardware Used: Core 2 Extreme QX6850 (3GHz)  EVGA nForce 680i SLI nForce 680i SLI chipset Asus P5E3 Deluxe X38 Express  Radeon HD 3870 X2 Radeon HD 3870 (x 2) Radeon HD 3850 Radeon HD 2900 XT GeForce 8800 GTX GeForce 8800 GT 2048MB Corsair PC2-6400C3 2 X 1GB 2048MB Corsair DDR3-1333 C7 2 X 1GB Integrated on board Western Digital "Raptor" 74GB - 10,000RPM - SATA

OS -  DirectX - Video Drivers - Synthetic (DX) - DirectX - DirectX - DirectX - DirectX - OpenGL -

Relevant Software: Windows Vista Ultimate DirectX 10 NVIDIA Forceware v169.09/v169.28 ATI Catalyst Bets v8.451 Benchmarks Used: 3DMark06 v1.0.2 Company of Heros - DX10 Crysis - DX10 Half Life 2: Episode 2* Enemy Territory: Quake Wars* * - Custom Test (HH Exclusive demo)

Performance Comparisons with 3DMark06 v1.0.2 Details: www.futuremark.com/products/3dmark06

3DMark06

3DMark06 is the most recent addition to the 3DMark franchise. This version differs from 3Dmark05 in a number of ways, and includes not only Shader Model 2.0 tests, but Shader Model 3.0 and HDR tests as well. Some of the assets from 3DMark05 have been re-used, but the scenes are now rendered with much more geometric detail and the shader complexity is vastly increased as well. Max shader length in 3DMark05 was 96 instructions, while 3DMark06 ups that number to 512. 3DMark06 also employs much more lighting and there is extensive use of soft shadows. With 3DMark06, Futuremark has also updated how the final score is tabulated. In this latest version of the benchmark, SM 2.0 and HDR / SM3.0 tests are weighted and the CPU score is factored into the final tally as well.

For reference, we've included a Radeon HD 3870 CrossFire benchmark scores in our graphs.  Please take note, however, that this is the ONLY dual-card setup represented in the results.

As you can see, the new Radeon HD 3870 X2 clearly outperforms every other single-card setup in 3DMark06, and finished essentially right on par with the dual-card Radeon HD 3870 CrossFire setup.

Drilling down into 3DMark06's individual Shader Model 2.0 and Shader Model 3.0 / HDR test results, we see the same performance trend.  In both tests, the Radeon HD 3870 X2 was as fast as the Radeon HD 3870 CrossFire setup, and measurably faster than any of the other single-card configurations.

Performance Comparisons with Half-Life 2: Episode 2 Details: www.half-life2.com

Half Life 2: Episode 2

Thanks to the dedication of hardcore PC gamers and a huge mod-community, the original Half-Life became one of the most successful first person shooters of all time.  And thanks to an updated game engine, gorgeous visual, and intelligent weapon and level design, Half Life 2 became just as popular.  Episode 2 offers a number of visual enhancements including better looking transparent texture anti-aliasing. These tests were run at resolutions of 1,280 x 1,024, 1,600 x 1,200 and 1,920 x 1,200 with 4X anti-aliasing and 16X anisotropic filtering enabled concurrently.  Color correction and HDR rendering were also enabled in the game engine as well.  We used a custom recorded timedemo file to benchmark all cards in this test.

Our first in-game benchmark tells almost the same story as 3DMark06.  In Half Life 2: Episode 2, the Radeon HD 3870 X2 clearly outperforms all of the single-card configurations at all resolutions, including the GeForce 8800 GTX.  The dual-card Radeon HD 3870 CrossFire setup was slightly faster at the lower resolution, but the X2 surpassed the dual-card setup once the resolution was increased. 

Performance Comparisons with Company of Heroes Details: www.companyofheroesgame.com

Company of Heroes

Relic Entertainment's World War II era real-time strategy game Company of Heroes was originally released as a DirectX 9 title for Windows.  But recent upates to the game have incorporated support for new DirectX 10 features that improve image quality and enhance the game's finer graphical details.  The game features a built-in performance test which which we used to attain the results below. Our Company of Heroes tests were run at resolutions of 1,280 x 1,024, 1,600 x 1,200 and 1920 x 1200 with 4X anti-aliasing and all of the game's image-quality related options set to their maximum values.

The Radeon HD 3870 X2 performed very well in the DirectX 10 Company of Heroes benchmark, but it couldn't quite keep pace with NVIDIA's GeForce 8800 GTX.  It was marginally faster then the dual-card CrossFire setup, and the other single-card setups, however.  And perhaps with better CrossFire scaling in this game it may be able to catch the GTX.

Performance Comparisons with ET: Quake Wars Details: www.enemyterritory.com

Enemy Territory:  Quake Wars

Enemy Territory: Quake Wars is Based on id's radically enhanced Doom 3 engine and viewed by many as Battlefield 2 meets the Strogg, and then some.  In fact, we'd venture to say that id took EA's team-based warfare genre up a notch or two.  ET: Quake Wars also marks the introduction of John Carmack's "Megatexture" technology that employs extremely large environment and terrain textures that cover vast areas of maps without the need to repeat and tile many small textures.  The beauty of megatexture technology is that each unit only takes up a maximum of 8MB of frame buffer memory.  Add to that HDR-like bloom lighting and leading edge shadowing effects and Enemy Territory: Quake Wars looks great, plays well and works high end graphics cards vigorously.  The game was tested with all of its in-game options set to their maximum values with soft particles enabled in addition to 4X anti-aliasing and 16x anisotropic filtering.

The Radeon HD 3870 X2 really liked our custom Enemy Territory: Quake Wars benchmark.  This time around, the Radeon HD 3870 X2 outpaced all of the other configurations, regardless of the resolution tested.  We should note, that during our time with the card, ATI supplied us with a number of driver releases and the final set resulted in some nice speed increases in this game.  With the initial drivers, the GTX was able to outpace the X2, but the tables turned as ATI was able to optimize the drivers further.

Performance Comparisons with Crysis Details: www.ea.com/crysis

Crysis

If you're at all into enthusiast computing, the highly anticipated single player demo of the hot, new, upcoming FPS smash-hit Crysis, should require no introduction. Crytek's game engine visuals are easily the most impressive real-time 3D renderings we've seen on the computer screen to date.  The engine employs some of the latest techniques in 3D rendering like Parallax Occlusion Mapping, Subsurface Scattering, Motion Blur and Depth-of-Field effects, as well as some of the most impressive use of Shader technology we've seen yet.  In short, for those of you that want to skip the technical jib-jab, Crysis is HOT.  We ran the SP demo with all of the game's visual options set to 'High' to put a significant load on the graphics cards being tested.

Crysis proved to be an interesting benchmark for the Radeon HD 3970 X2.  Overall, it finished just a bit behind the dual-card Radeon HD 3870 CrossFire setup and a frame or two ahead of the GeForce 8800 GTX.  Initially, however, Crysis didn't seem to scale well for us.  And it wasn't until we got our hands on a new set of drivers that things fell into place for the X2.  We point this out because the game has been out for many weeks, and it wasn't until a few days ago that the CrossFire began working properly during testing, which is a problem inherent to multi-GPU configurations - without the necessary driver support, that second GPU won't help performance at all.

We also did some quick testing of the Radeon HD 3870 X2's UVD video processing engine, in terms of both image quality and CPU utilization with our HQV and H.264 playback tests.

HQV - DVD Video Decoding and Playback Quality Pure Video HD vs. UVD

HQV is comprised of a sampling of SD video clips and test patterns that have been specifically designed to evaluate a variety of interlaced video signal processing tasks, including decoding, de-interlacing, motion correction, noise reduction, film cadence detection, and detail enhancement. As each clip is played, the viewer is required to "score" the image based on a predetermined set of criteria. The numbers listed below are the sum of the scores for each section. We played the HQV DVD using the latest version of Cyberlink's PowerDVD, with hardware acceleration for AMD AVIVO HD and NVIDIA PureVideo HD extensions enabled.

Both ATI's and NVIDIA's current generation GPUs have no trouble with SD video playback.  The Radeon HD 3870 X2 and GeForce 8800 GT put up near perfect scores in the HQV test.  In case you're not familiar with HQV, 130 points is the maximum score attainable.  At 128 points, a PC equipped with either of these graphics cards plays back DVD video at quality levels better than the vast majority of set-top DVD players on the market.

H.264 Video Decoding And Playback Performance Sipping CPU Cycles

Next we conducted a test using an H.264 encoded movie trailer clip for "Beowulf" which is available for download on Apple's QuickTime website.  The CPU utilization data gathered during these tests was taken from Windows Vista's built-in Performance Monitor. The graphs show the CPU utilization for a GeForce 8800 GT and a Radeon HD 3650 using PowerDVD to playback the QuickTime clip.

 
GeForce 8800 GT



 
Radeon HD 3870 X2

With a powerful quad-core processor at the heart of our test system and an unencrypted HD video clip being played, both the GeForce 8800 GT and Radeon HD 3870 X2 averaged low, single-digit CPU utilization in this test.  We should note that with hardware acceleration disabled, playing this video clip results in about 12% - 15% CPU utilization, so there is a marked improvement with both PureVideo HD and UVD.

Before we bring this article to a close, we'd like to cover a few final data points. Throughout all of our benchmarking and testing, we monitored how much power our test system was consuming using a power meter and also took some notes regarding its noise output. Our goal was to give you all an idea as to how much power each configuration used and to explain how loud the configurations were under load. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the video cards alone.
  

Total System Power Consumption & Acoustics It's All About the Watts and Decibels

The Radeon HD 3870 X2 reminds us a bit of Dr. Jekyll and Mr. Hyde when looking at its power consumption characteristics.  Even though the card has a PCI Express switch, dual GPUs, and double the number of memory chips than any other card listed here, its idle power consumption wasn't all that bad.  It was much higher than any of the single-GPU Radeons, but it was in-line with NVIDIA's high-end offerings.  While under load though, the Radeon HD 3870 X2 used plenty of juice, and sucked down a bit more power than the GeForce 8800 GTX.  Not bad actually, when you consider there are two GPUs on the 3870 X2, versus the GeForce 8800 single GPU design.

In terms of acoustics, the Radeon HD 3870 X2 also had split personalities.  When first powered on, the card's fan spins up to a very high-speed and it generates a ton of noise.  It quickly spins down, however, and while idling it is relatively quiet.  We should also note that during normal gaming and throughout benchmarking, the Radeon HD 3870 X2's fan never spun up to its highest speed.  Although the potential is there for quite a bit noise, we have to say that in practice, the Radeon HD 3870 X2 isn't much louder than any other high-end graphics card offering currently on the market.

We’re cautiously optimistic about the Radeon HD 3870 X2.  On one hand, our benchmark results are undeniable; the card simply performed well throughout testing and it marks AMD’s re-entry into the high-end 3D graphics card market.  During the course of testing, however, ATI supplied us with three different sets of drivers, with each set either improving performance or fixing bugs (the final set was used for testing).  This brings us to an important point.  Because the Radeon HD 3870 X2 is essentially “CrossFire on a card”, the X2’s performance is determined by how well the card’s drivers scale in a particular game.  If a new game hits store shelves and the drivers don’t recognize the executable, the $449-$499 Radeon HD 3870 X2 will perform much like a single-GPU Radeon HD 3870 that is half the price.  ATI assures us their software team will try to minimize this situation, but it will be an issue at some point in time no matter how hard they work unless a universally compatible multi-GPU rendering technique is devised.  This is something you must be aware of if you’re contemplating the purchase of Radeon HD 3870 X2.

For now, AMD should be proud of their achievements.  We’re sure many ATI loyalists are going to look at today’s launch as a huge success.  Ultimately though, the real long-term value of the Radeon HD 3870 X2 will be determined by AMD’s driver team.  If they work closely with game developers and consistently improve performance and scaling for existing and upcoming games, then the X2 is worthy of praise.  If the drivers can’t keep pace with hot game releases, however, and users have to wait weeks, or even months to fully utilize their graphics card, that would be a great disservice.  We’re hoping for the best, because the hardware is impressive indeed.