Multiple Monitors: To Eyefinity and Beyond

The multi-monitor desktop has been a trend that has come and gone over the years, but recent announcements have it percolating back up to the top of the tech world. Dual-monitor outputs are now standard even on low-end PCs and Matrox remains a player with its TripleHead2Go display upgrade, but the latest multi-monitor designs take things a bit further.

First, it was AMD with its innovative Eyefinity announcement. Now Nvidia has made a splash with its 3D Vision Surround technology. Both look to improve on basic Windows functionality and give power users more options.

With the power of even mainstream graphics cards increasing at exponential rates and LCD costs dropping by the day, concerns over performance and cost have faded and multi-monitor demand has grown accordingly. Some of these setups are for gaming or entertainment systems, but the corporate uses of this technology are just as compelling, such as the potential for greater employee efficiencies.

Putting the Aye in Eyefinity

AMD started the latest wave of multi-monitor implementations, as its ATI Eyefinity launch provided a very powerful and flexible option for this growing market segment. At its base, AMD has incorporated up to six display lanes in each of its latest DirectX 11 GPU models. These Radeon HD 5000 series graphics processors are powerful enough to handle the extra load of six concurrent displays, even for 3D applications.

Eyefinity is a multi-purpose, highly segmented technology with tangible benefits for just about every type of PC user. Home entertainment aficionados with Radeon HD 5000-based cards can game or enjoy movies across multiple monitors, while home office workers can span their desktops for higher productivity. Professional users can also achieve the same effect using an ATI FirePro workstation graphics card.

The number of supported monitors depends on the card type and model. The base minimum for ATI Eyefinity technology is three active display outputs. The flagship Radeon HD 5870 Eyefinity 6 Edition crams six mini-DisplayPort connectors onto a single card. The Radeon HD 5450 to HD 5970 DisplayPort-ready cards (including the ATI Mobility Radeon HD 5400 Series) support up to six monitors at the high-end, while the ATI FirePro checks in with a maximum of four displays per card.

DisplayPort technology is required for Eyefinity usage, and although this will rankle DVI monitor owners, its ability to scale to additional display lanes on a single GPU is what really drives Eyefinity. Many high-end LCD monitors include native DisplayPort inputs, but those with DVI support can still make use of this technology using DisplayPort adapters or dongles. This isn't a perfect solution, especially as high-resolution, active dongles need to be powered, but there really is no way around it if you want a single video card to drive up to six displays. DisplayPort also offers significantly higher bandwidth than DVI, which is needed at these ultra-high resolutions.

ATI Eyefinity supports the basic clone and extended multi-monitor setups, but adds a Single Large Surface (SLS) option in which the operating system, instead of adding clone or extended displays one at a time, identifies a group of displays as a single, high-resolution monitor. The technology can also segment these further; a 3-by-2 group of monitors can easily be changed to a pair of 3 by 1 groups.

One inherent issue with this type of multi-monitor configuration is the potential obtrusiveness of the LCD bezels, buttons and lights. To help combat this, Eyefinity has a feature called Bezel Compensation, which removes the pixels that would be displayed near the edge of each LCD, thereby eliminating the potential for image jump as your eyes track from monitor to monitor. This feature emulates how your eyes work with real-world obstructions like a window frame, with the image "hidden" behind the bezel.

There are also thin-bezel LCDs and stands available now, and some vendors will be offering Eyefinity-validated displays with negligible bezel width. A nearly bezel-free LCD is still some ways off, and will be expensive when released, especially as demand from consumers has not been high enough to offset the production costs.

Support for business and productivity 2D applications should be seamless with Eyefinity and SLS, as the operating system will simply view the multi-monitor as one large display. Where it gets a little dicey is with resolution-specific 3D games and applications, which will need to be tested and validated on Eyefinity. OS support is currently limited to Windows 7 and Vista, although AMD is working on a Linux update.

Using six monitors can really drive the resolution through the ceiling -- sextupling standard 24-inch LCDs can yield a virtual display of 5,760 by 2,400 pixels, and with a sextet of 30-inch behemoths, it ramps up to an astounding 7,680 by 3,200. In this type of demanding scenario, not only is a powerful GPU needed, but also the software powering it has to be top-notch. Both application support and overall image quality need to be high before ATI Eyefinity has a chance in the mass market.

Nvidia's Wraparound Gaming

Nvidia also fired back at ATI Eyefinity, but only using a single barrel. Rather than offering a highly flexible technology like Eyefinity, Nvidia seems to have gaming tunnel vision with its 3D Vision Surround product launch. Other than that, its base functionality somewhat mirrors that of AMD's, with one major difference: 3D.

3D is all the rage when it comes to summer blockbusters, and Nvidia is obviously betting on the technology catching on at the home level as well. However, there are definitely challenges, and hardware support is one of them. Due to the strict requirements for a 3D-certified display, only a limited number of monitors and other equipment is supported.

The graphics-card configuration is less flexible than Eyefinity, with a second card in an SLI setup required if you want to move past dual-monitor 3D, adding to the total cost. The 3D Vision Surround technology also supports up to a maximum of only three displays, using standard DVI and dual-DVI inputs. There is also a 2D option dubbed Nvidia Surround, but again, this is targeted exclusively at gamers and has no real business use.

3D Vision Surround is the first multi-display 3D gaming technology to hit the market, but at its heart, Nvidia has simply added multi-monitor support to its existing 3D Vision technology. Nvidia's 3D Vision Surround is a pure gaming product. It is also a cumbersome and expensive one, and even playing the 3D fad card should not do anything to increase adoption rates.

Pushing the Envelope

The current graphics market is an interesting one, as both AMD and Nvidia continue to embark on record-breaking release schedules, but with ever-declining payoffs for doing so. Most new games are just ports from five-year-old Xbox 360/PS3 console hardware, and these don't exactly push a top-end 2010 graphics card.

That is one reason why both companies are attempting to utilize their powerful GPUs in any way possible, such as with Nvidia CUDA or ATI Stream. Multi-monitor setups are certainly another way to make use of this excess power and make the latest and greatest GPU look more attractive, especially running at outlandish resolutions like 7,680 by 3,200.

In order to drive the ultra-high resolutions of these latest multi-monitor setups, you will need a killer GPU or two under the hood. None of those old "integrated video is just fine" rationalizations; driving three 3D or six 2D displays simultaneously demands a far more substantial dedicated graphics card.

Both vendors' self-serving agendas aside, ATI Eyefinity is the clear winner. It's more powerful, more flexible and offers a wider range of features and options catering to virtually all user groups. The ability to create an SLS display out of multiple monitors using virtually any configuration is a powerful one, as is the ability to drive six displays using a single card.

The only stumbling block is DisplayPort and the added cost of LCD displays supporting this new technology. The ATI Radeon HD 5000 series is not that expensive at the mainstream level, but DisplayPort-ready LCDs monitors are usually limited to high-end and higher-priced models. If AMD can clear this up and we see a wave of affordable DisplayPort monitors, then Eyefinity has a chance to really take off.