Thursday, October 13, 2011

AMD Radeon HD 6870 CrossFire with 5x1 Eyefinity


Way back in September of ’09, AMD launched the Radeon HD 5800 series, and along with it officially unveiled its Eyefinity multi-display technology, which now pervades all Radeon HD 5000 and 6000 series cards in one form or another. Leading up to the release of the 5800 series, AMD tried to keep Eyefinity a close guarded secret, so its arrival was a pleasant surprise for most consumers and a not so pleasant one for rival NVIDIA perhaps. Dual and multi-screen gaming wasn’t new per say, just ask die-hard Flight Simulator fans who have been doing it for years.  However, AMD’s implementation was much more elegant than any of hacks or other solutions available in the past. And on higher-end cards, it allowed for easy integration of up to six monitors, which was unheard of at the time.


Since its initial introduction, AMD has continued to refine and optimize Eyefinity, while also working with game developers to ensure proper support in a multitude of titles. CrossFire support, which was available at launch, came a while back as well. DisplayPort-enabled monitors have gotten more affordable, cheap DP-to-DVI adapters have been made available, and the performance of more mainstream graphics cards has gotten good enough to push multiple displays with decent framerates, making the cost of entry somewhat palatable for even an extreme three or six monitor setup.
Available AMD Eyefinity Configurations 
Part of the allure of AMD Eyefinity is its flexibility. There are many different screen configurations that can be supported, some of which are represented above. Depending on your needs, and desk real estate, monitors can be arranged in a multitude of different ways, with a mix of extended or mirrored desktops. In addition, and this is what set Eyefinity apart from legacy solutions, screens can also be combined in a what AMD calls a Display Group and they’ll act as a single large surface (AMD actually calls the underlying software that’s part of the Catalyst Control Center SLS).

Samsung's Sexy Six Screen Setup...
The single large surface can span up to six monitors, resulting in a huge expanse of screens with a massive number of pixels in play. A typical six screen setup, for example, comprised of relatively affordable 22” LCDs with native resolutions of 1920x1080, setup in a 3x2 arrangement, would have a combined resolution 5760x2160; that’s a boatload of pixels.

One of the more recent display group configurations to be supported by AMD is a 5x1 portrait arrangement. This king of setup is interesting because it’s more appealing to gamers than a six-screen 3x2 setup. With six screens in a 3x2 arrangement, the center of the SLS surface falls on the monitor bezels, which is not ideal for FPS games in particular. With a 5x1 setup, the center of the SLS surface is a full monitor, ideally centered on the gamer, and the remaining four screens extend outward, offering an unparalleled field of view.

  

  
PowerColor Radeon HD 6870 2GB Eyefinity 6 Edition
With the performance of more mainstream cards on the rise, monitor prices on a downward slide, and support for 5x1 Eyefinity available (sort of—more on that later), we decided to see what a pair of Radeon HD 6870 cards running in CrossFire mode could do with a quintet of screens out in front.

The cleanest way to pull off a 5x1 Eyefinity configuration, without using an array of adapters is with a card that has at least five, similar outputs, connected to matching monitors. To that end, we got our hands on a pair of PowerColor Radeon HD 6870 2GB Eyefinity 6 Edition cards, which have six mini-DP outputs. These cards sport 900MHz GPU clocks, with 2GB of GDDR5 memory running at 1050MHz (4.2Gbps effective), so they’ll perform right on part with reference Radeon HD 6870 cards, which have the same clocks, in most scenarios. The PowerColor card’s 2GB frame buffer, however, will give the card the breathing room necessary to support the ultra-high effective resolution of five screens linked together. We’re seeing 1GB graphics cards choke on some of today’s games when a single 30” monitor with a 2560x1600 resolution is used; at 5760x2160 1GB isn’t going to cut it with newer titles.


Before we get down to the nitty gritty, we want to give you all a sense of just how many pixels users have available when sitting in front of a five-screen Eyefinity display group, using monitors with a native resolution of 1920x1080. The two images below are actual screen captures of the Windows desktop and a game, Alien vs. Predator, at resolutions of 5400x1920.

Click For An Enlarged View
Are those images freakin’ huge or what? The benefits of gaming or working with multiple screens should be apparent. The field of view in games is so wide, you’ll be able to see much more in your periphery, which has obvious benefits. When working on a desktop this big, users can simply see more in front of them. That image is a recent five-page review, with all five pages open at once.

We tested the PowerColor Radeon HD 6870 Eyefinity 6 Edition cards on a Gigabyte GA-EX58-UD5 motherboard powered by a Core i7-980X six-core processor and 6GB of OCZ DDR3-1333 RAM. The first thing we did when configuring the test system was enter the system BIOS and set all values to their "optimized" or "high performance" defaults. Then we manually configured the memory timings (DDR3-1333, CAS 7) 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:Core i7 980X (3.3GHz)
Gigabyte EX58-UD5 (X58 Express)
6GB OCZ DDR3-1333
Western Digital Raptor 150GB
Integrated Audio
Integrated Network

Relevant Software:
Windows 7 Ultimate x64
DirectX April 2011 Redist
ATI Catalyst v11.4 Preview
Benchmarks Used:
Unigine Heaven v2.5
Futuremark 3DMark Vantage
Futuremark 3DMark11
FarCry 2
Just Cause 2
Alien vs. Predator
Metro 2033
Lost Planet 2
F1 2010







Our first group of tests show the PowerColor Radeon HD 6870 2GB Eyefinity 6 Edition cards offering excellent performance scaling when running in CrossFire mode. All of the applications show big performance improvements when moving from a single cards to dual cards. We'll summarize them all on the next page, after running through a few more, and then we'll get to the wild stuff.
Next up we have a few more game tests to see how well performance scales with Radeon HD 6870 cards running in CrossFire mode.








In the remaining tests, we again see the PowerColor Radeon HD 6870 2GB Eyefinity 6 Edition cards offering solid performance and good scaling when running in a two-card CrossFire configuration. In some cases, like Metro 2033 and Alien vs. Predator in particular, the games when from a just playable 30-ish frames per second, to a much more fluid and smooth 60-ish FPS.
To better show just how much the performance in each game improved, we’ve summarized them all here. Upgrading from a single card to two cards, with the applications we used for testing, resulted in a minimum performance increase of 82% and a max of 99% (a 100% improvement is the theoretical maximum, which unlikely to happen due to the overhead associated with the various complexities of running a multi-GPU setup).

Now that we’re clean that a pair of Radeon HD 6870 cards running in CrossFire can offer some serious performance using a single monitor, let’s see how they behave with five screens connected...
Performance Summary:  We set out to ascertain two things at the beginning of this project, to see how well a pair of Radeon HD 6870 cards scaled in CrossFire mode using recent drivers and to see how well the setup performed with a five-screen 5x1 Eyefinity configuration. Our tests showed excellent performance scaling (between 82% and 99%) in CrossFire mode with the applications we used and we achieved playable framerates at an effective resolution of 5400x1920 using Eyefinity 5x1, even in some very taxing games like Alien vs. Predator and Metro 2033, albeit with the quality settings dialed down a notch or two.
Throughout testing for this article, however, we also found out a few other things that need to be pointed out. While 5x1 Eyefinity is undoubtedly cool, AMD still has a lot of work to do in our opinion. Support for the mode was available in the Catalyst 11.4 preview drivers, but it was removed in the 11.5 drivers currently posted. We’re told 5x1 support will be back in a future driver, but aren’t sure if it’ll be in the 11.6 version, which should be posted soon, or a later revision.

We also had a heck of time finding games that would run properly. The four we showed here had no problem, and Dragon Age II worked as well, but we scrapped that title due to annoyances with EA’s download manager app (that’s another story altogether, though). Games like Left 4 Dead 2, Bad Company 2, H.A.W.X., or Dirt 2, which worked in our original Eyefinity 6 preview, wouldn’t run on all of the screens. Neither would some newer titles like Dirt 3, nor F1 2010, Just Cause 2, and the list goes on. In all fairness, most of those games worked in a 3x1 configuration, but the newer 5x1 mode just wasn't happening, for now.

Another niggle we had with 5x1 Eyefinity had to do with the monitors being used. This is no fault of AMD’s mind you, but with five screens spread out in portrait mode, users must be mindful of the viewing angles of the screens. Vertical viewing angles aren’t typically as good as horizontal viewing angles, so proper positioning of the screens is a must.  Again, perhaps with different LCDs at play, your experience could be better or worse we suppose.

Cost with a setup like this is obviously another concern too, but truth be told, it’s not that outlandish in the grand scheme of things. A pair of NVIDIA GeForce GTX 580 cards and a single large monitor---which is a setup we know many enthusiasts might currently have—costs around $1300 to $1500 currently. The five 22” Dell screens we used and two PowerColor Radeon HD 6870 2GB Eyefinity 6 Edition cards would be about $1700, which isn’t all that far off. A setup like this isn’t for everyone, and we’d recommend using higher-end graphics cards like the Radeon HD 6970 to take performance up a few notches.  That said, a display configuration like this is fun to see in action and there are obvious benefits for productivity as well with all that screen real estate. Then again, who’s going to get any work done with a wild setup like this?

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