AMD Radeon HD 6950 & HD 6970 CrossFireX

[PAGETITLE=Introduction][Top Ad] AMD a couple of weeks ago released its first Radeon HD 6900 graphics card models, and at the time our article was published (about a week late due to various circumstances), we were unable to include CrossFireX performance as we had hoped. So, to help fill in that void, this article will tackle dual-GPU HD 6950 and HD 6970 configurations across our regular suite. As we've come to expect from AMD, pairing up two GPUs to act together is a simple process. After both cards are installed and power connectors hooked up, all that's needed is a simple CrossFireX bridge to mate the cards. This process is identical to NVIDIA's SLI, and software-wise, both AMD and NVIDIA offer similar feature-sets. One aspect we haven't tackled in the past, but we plan to in the near-future, is CrossFireX vs. SLI. NVIDIA touts more often than AMD that its dual-GPU solution is superior, and that's something we'd like to put to an honest test. One thing's for sure, though, and that's that dual-GPU tech has improved vastly ever since its introduction. In the earlier days of multi-GPU, we'd be lucky to see 150% of the performance of just one card, but today, when paired with the right software, we can actually see performance increases of up to 200%. In some rarer cases, we can even see that 200% mark exceeded, which goes to show just how mature these configurations are in today's landscape. In the photo above (can you tell that my camera's external flash is broken?) sits AMD's Radeon HD 6970 and HD 6950 - two of each. As you can no doubt tell, the cards all look identical, and for the most part, there's little different between them. The GPU dies are of course varied between the two, but on the larger of the two cards, HD 6970, an 8-pin connector is required along with a 6-pin - rather than require two 6-pins. There's not a lot to discuss here that hasn't been touched upon in our launch article, but for the sake of interest, you can review AMD's current line-up below. At the current time, AMD doesn't offer a dual-GPU version of an HD 6000 card, but if all goes according to plan, we should be seeing the HD 6990 in early 2011. How it will compare to today's CrossFireX solutions is yet to be seen. Model Core MHz Mem MHz Memory Bus Width Processors Radeon HD 6970 880 1350 2048MB 256-bit 1536 Radeon HD 6950 800 1250 2048MB 256-bit 1408 Radeon HD 6870 900 1050 1024MB 256-bit 1120 Radeon HD 6850 775 1000 1024MB 256-bit 960 Radeon HD 5970 725 1000 2048MB 256-bit 1600 x 2 Radeon HD 5870 Eyefinity 6 850 1200 1024MB 256-bit 1600 Radeon HD 5870 850 1200 1024MB 256-bit 1600 Radeon HD 5850 725 1000 1024MB 256-bit 1440 Radeon HD 5830 800 1000 1024MB 256-bit 1120 Radeon HD 5770 850 1200 1024MB 128-bit 800 Radeon HD 5750 700 1150 512MB - 1GB 128-bit 720 According to AMD's official specifications page for the HD 6970, a 550W power supply is required for a single GPU configuration. That assumes that the 8-pin connector can deliver at least 150W, while the 6-pin can deliver 75W. Combined, this safely covers the card's TDP "typical" rating of 190W. Unfortunately, the company doesn't give specific information regarding CrossFireX power supply requirements, but given what we've seen in our GPU stress-tests, we'd have to recommend at least an 800W unit, with at least 80% efficiency. For dual HD 6950s, I'd recommend a similar unit, as that configuration draws just about 50W less at full load. Before continuing, it's important to note that due to architecture limitations, running six monitors on both GPUs is not possible. For that, you'd need to purchase a DisplayPort hub and connect it to the first card. For three monitors, all can be run off of the top card without issue. Without further ado, let's take care of our testing methodology explanations, and then we'll get right into our test results. [PAGEBREAK][PAGETITLE=Test System & Methodology] At Techgage, we strive to make sure our results are as accurate as possible. Our testing is rigorous and time-consuming, but we feel the effort is worth it. In an attempt to leave no question unanswered, this page contains not only our testbed specifications, but also a detailed look at how we conduct our testing. Test Machine. The below table lists our testing machine's hardware, which remains unchanged throughout all GPU testing, minus the graphics card. Each card used for comparison is also listed here, along with the driver version used. Each one of the URLs in this table can be clicked to view the respective category on our site for that product. Component Model Processor Intel Core i7-975 Extreme Edition - Quad-Core @ 4.05GHz - 1.40v Motherboard Gigabyte GA-EX58-EXTREME - F13j BIOS (08/02/2010) Memory Corsair DOMINATOR - 12GB DDR3-1333 7-7-7-24-1T, 1.60v ATI Graphics Radeon HD 6970 2GB CrossFireX (Reference) - Catalyst 10,12 Beta Radeon HD 6950 2GB CrossFireX (Reference) - Catalyst 10.12 Beta Radeon HD 6970 2GB (Reference) - Catalyst 10,12 Beta Radeon HD 6950 2GB (Reference) - Catalyst 10.12 Beta Radeon HD 6870 1GB (Reference) - Catalyst Oct 5, 2010 Beta Radeon HD 6850 1GB (Sapphire Toxic) - Catalyst 10.11 Radeon HD 6850 1GB (Reference) - Catalyst Oct 5, 2010 Beta Radeon HD 5870 1GB (Sapphire) - Catalyst 10.8 Radeon HD 5850 1GB (ASUS) - Catalyst 10.8 Radeon HD 5830 1GB (Reference) - Catalyst 10.8 Radeon HD 5770 1GB (Sapphire FleX) - Catalyst 10.9 Radeon HD 5770 1GB (Reference) - Catalyst 10.8 Radeon HD 5750 1GB (Sapphire) - Catalyst 10.8 NVIDIA Graphics GeForce GTX 480 1536MB (Reference) - GeForce 260.63 GeForce GTX 470 1280MB (EVGA) - GeForce 260.63 GeForce GTX 460 1GB (EVGA) - GeForce 260.63 GeForce GTX 450 1GB (ASUS) - GeForce 260.63 Audio ASUS Xonar D2X Storage Seagate Barracuda 500GB 7200.11 Power Supply Corsair HX1000W Chassis Cooler Master HAF X Full-Tower Display Gateway XHD3000 30" Cooling Corsair H50 Self-Contained Liquid Cooler Et cetera Windows 7 Ultimate 64-bit When preparing our testbeds for any type of performance testing, we follow these guidelines: General Guidelines No power-saving options are enabled in the motherboard's BIOS. Internet is disabled. No virus scanner or firewall is installed. The OS is kept clean; no scrap files are left in between runs. Hard drives affected are defragged with Diskeeper 2010 prior to a fresh benchmarking run. Machine has proper airflow and the room temperature is 80°F (27°C) or less. To aide with the goal of keeping accurate and repeatable results, we alter certain services in Windows 7 from starting up at boot. This is due to the fact that these services have the tendency to start up in the background without notice, potentially causing inaccurate test results. For example, disabling "Windows Search" turns off the OS' indexing which can at times utilize the hard drive and memory more than we'd like. The most important services we disable are: Diskeeper 2010. Windows Defender. Windows Error Reporting Service. Windows Event Log. Windows Firewall. Windows Search. Windows Update. The full list of Windows services we assure are disabled is large, but for those interested in perusing it, please look here. Most of the services we disable are mild, but we go to such an extent to have the PC as highly optimized as possible. Game Titles. At this time, we benchmark with three resolutions that represent three popular monitor sizes available today, 20" (1680x1050), 24" (1920x1080) and 30" (2560x1600). Each of these resolutions offers enough of a variance in raw pixel output to warrant testing with it, and each properly represent a different market segment: mainstream, mid-range and high-end. Because we value results generated by real-world testing, we don't utilize timedemos. The possible exceptions might be Futuremark's 3DMark Vantage and Unigine's Heaven 2.1. Though neither of these are games, both act as robust timedemos. We choose to use them as they're a standard where GPU reviews are concerned. All of our results are captured with the help of Beepa's FRAPS 3.2.3, while stress-testing and temperature-monitoring is handled by OCCT 3.1.0 and GPU-Z, respectively. For those interested in the exact settings we use for each game, direct screenshots can be seen below: Colin McRae: Dirt 2. Just Cause 2. Mafia II. Metro 2033. StarCraft II. [PAGEBREAK][PAGETITLE=Colin McRae: Dirt 2] It's not that often that faithful PC gamers get a proper racing game for their platform of choice, but Dirt 2 is one of those. While it is a "console port", there's virtually nothing in the game that will make that point stand out. The game as a whole takes good advantage of our PC's hardware, and it's as challenging as it is good-looking. Manual Run-through: The race we chose to use in Dirt 2 is the first one available in the game, as it's easily accessible and features a lot of GPU-pounding effects that the game has become known for, such as realistic dust and water effects, a large on-looking crowd of people and fine details on and off the track. Each run-through lasts the entire two laps, which comes out to about 2.5 minutes. Depending on the resolution, CrossFireX can go from being "nice" to "great" to "awesome!". At 1680x1050, the average FPS on dual HD 6970s compared to the single was +56%, while at 2560x1600, that figure soared up to a much more impressive +77%. This is a trend that's common with most high-end cards, as lower resolutions are not often able to push a GPU quite so hard. There's of course a major difference between 1.7 million pixels (1680x1050) and 4.1 million (2560x1600), that's for sure. [PAGEBREAK][PAGETITLE=Just Cause 2] Just Cause 2 might not belong to a well-established series of games, but with its launch, it looks like that might not be the case for long. The game offers not only superb graphics, but an enormous world to explore, and for people like me, a countless number of hidden items to find around it. During the game, you'll be scaling skyscrapers, racing through jungles and fighting atop snow-drenched mountains. What's not to like?...

AMD Radeon HD 6950 & HD 6970 CrossFireX

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Rob Williams