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Seeing more, doing more; a guide to putting multiple monitors to work, or play

Posted by Jon Peddie on April 16th 2010 | Discuss
Categories: Hardware Review
Tags: amd gaming production multiscreen

We have been proponents of multi-screen displays forever, and have run almost every combination there is for over two decades now. Possibly the largest monitor in a cluster we ever had was a Sony 24-inch CRT Trinitron that weighed over 300 pounds.

We’ve cabled notebooks to external monitors and built really powerful workspaces of three and four displays with effective resolutions of 4800 x 1200. We’ve tried the various Matrox Dual and TripleHead2Go combinations, and for the money we were pretty impressed, but the burden of driver tweaks limited the range of applications. The TripleHead2Go maps the GPU’s external display frame buffer into a long display. Since introduction, Matrox has expanded the TripleHead2Go to support 3 x 1680 x 1050 with their DP Digital Edition for $279, plus the cost of an AIB with adequate memory (min. 1 GB).

We’ve used multiple AIBs to drive four screens and even experimented with combinations of AIBs and IGPs in the same system for driving multiple screens. They all worked and for the most part were satisfactory. A couple of combinations lacked the update speed needed for FPS high-resolution game play.

Nvidia has taken their stereographic 3D (S3D) technology, which they call 3D vision, and they have allied it to two Nvidia AIBs running in SLI mode to deliver three monitors in S3D. They demonstrated that at CES with three high-resolution projectors and a really wide projection screen. You could set up such a system using three 22-inch Samsung 120 Hz monitors on your desktop. The Samsung 120 Hz monitors only display 1680 x 1050 and have pretty wide bezels, and Nvidia hasn’t yet come out with a bezel adjustment (although they have the people in house from Appian who certainly know how to do that.)

Using multiple monitors can be challenging in several ways:

• Desk space. It can take up space—three 30-inch monitors in portrait mode will require 81-inches—almost seven feet (6.75), and a more modest use of three 22-inch monitors will still require five feet. However, if you have the height (20 to 27 inches plus a couple inches for the stand, three display in portrait configuration only needs 54 inches or 4.5 feet, which is close to the size of most desks albeit with a little overhang. Twenty-two inch monitors can be setup vertically in portrait mode and use just 36-inches or three feet of desk space. It’s a lot more tolerable today with flat-screen displays than it was when we were using CRTs that were often deeper than they were high or wide, three of those would eat your whole desk.
• Mounting hardware. If you go for more than three monitors sitting on a desk, and/or if you want the monitors to be correctly aligned with each other physically, you’ll need to invest in VESA mounting brackets.
• Power. A 30-inch monitor draws 170 watts. Three of them need 510 Watts. A 22-inch display needs 40 watts and six of them will require 240 watts. Add to that about 150 watts for the PC and you’re straining the delivery service of the circuit breaker of a U.S. three-pin socket. You’ll also need a power distribution assembly—i.e., an extension cord or “power strip” for all the monitors, PC and probably your sound system. Here is a place not to cheap out, and a multi-three pin strip with multiple and individual circuit breakers is ideal, it’s somewhat difficult to find (although Monster has some interesting gear).
• Price. This has become so much more manageable with the rapid drop in monitor prices. A 1920 x 1080 22-inch monitor can be bought in the U.S. for just $170 with DVI ($239 with DisplayPort). Three would be $510 ($717), and six, if you couldn’t negotiate a quantity discount, would set you back $1,020 ($1,434). Add to that the graphics processor(s).
• Graphics processors. The AIB(s) will cost from $60 (ATI Radeon HD5450 with one DVI port, a VGA port, and a DisplayPort) to $479 (for an ATI Radeon 5870 Eyefinity6 with six DisplayPorts.) Other combinations of multiple graphics AIBs (e.g., two Nvidia AIBs in SLI mode, or two ATI AIBs in Crossfire mode, or two of almost any AIB in a LucidLogix system), and/or such a combination with the VGA/DVI/HDMI output of a modern IGP.

So we’ve dealt with all those things several times and in several ways. And our latest adventure was six 22-inch, 1920 x 1080 60Hz LCD (Dell) DisplayPort monitors, powered by an ATI Radeon HD 5870 Eyefinity6. We’ve reviewed the Radeon HD 5870 previously (Tech Watch September 29, 2009 • Volume 9, Number 20, p.44 ) and the Eyefinity6 version is basically the same AIB with two notable additions—six DisplayPort connectors on the rear panel and 2 GB of DDR5 memory.

The specifications are exactly the same, but the power consumption a little higher for twice as much memory. And so ATI has had to go from 6+6 to 8+6 pin connections.

• Engine clock speed: 850 MHz.
• Processing power (single precision): 2.72 TeraFLOPS.
• Processing power (double precision): 544 GigaFLOPS.
• Polygon throughput: 850M polygons/sec.
• Data fetch rate (32-bit): 272 billion fetches/sec.
• Texel fill rate (bilinear filtered): 68 Gigatexels/sec.
• Pixel fill rate: 27.2 Gigapixels/sec.
• Anti-aliased pixel fill rate: 108.8 Gigasamples/sec.
• Memory clock speed: 1.2 GHz.
• Memory data rate: 4.8 Gbps.
• Memory bandwidth: 153.6 GB/sec.
• Maximum board power: 228 Watts.
• Idle board power: 27 Watts.

The AIB, which is being referred to as the ATI Radeon HD 5870 E6 sells for $479 (the ATI Radeon HD 5870 for $399).

More—I want to see more

We’ve been playing with a six-screen EyeFinity system for the past month, testing games on it and beta drivers. If you’re a big fan of big displays and have the room to accommodate them, this is the system for you. An ATI Radeon HD 5870 Eyefinity 6 Edition AIB with 2GB of GDDR5 memory drives the displays. The system is going to be even more ideal when Samsung’s new monitors with thin bezels ship later this year (see page 19).

Physical. Setting them up was challenging because of the size involved. We used 22-inch 1920x1080 Dell displays and I could barely imagine what it would have been like to have 30-inch monitors. The monitor type and mounting apparatus is critical. We learned the (hard way) that COTS monitors aren’t designed for stacking and in fact, they’re downright hostile to the idea. That’s because the outside surfaces of the bezels are not square nor flat for most monitors as they try to use a sleek rolled off design. The six 22-inch monitors occupy a space that is 61 x 25 inches, plus whatever height off the table you allow—we put ours right on the desktop’s surface.

The system starts up with all six displays in clone mode.

You use the ATI Catalyst control panel to setup a group, and there is just about every combination imaginable, 1x3, 3x1, 2x3, 3x2, etc. The physical setup pretty much dictates the choice and so we went with 3x2. After a few clicks the system will ask you if the correct monitor is lit for the physical layout (it usually isn’t and you work your way around a 3x2 matrix setting up the positions, it’s a nice tool. When you’ve finished that operation (a onetime thing, but must be done any time you change the configuration) you’re ready to go. One last question is asked—do you want to do a bezel adjustment? This is a choice that can be useful if you are playing games and would prefer the effect of looking through six windows—with the bezel (the window frame) obscuring part of the image. That gives you a more accurate geometric result, but can cause you to move the image back and forth to see what’s hidden by the frame. Once all the setup is done, you can (should) reboot and then you get a full, extended single surface screen.

The first time you see the system boot up like this it’s really quite breath taking.

Raw resolution

A single 22-inch monitor has the characteristics shown in Table 1 (in inches).

In a 3x2 landscape mode the characteristics become the measurements shown in Table 2 (in inches).

Modes of operation

With a multi-display system there are two basic uses—productivity and entertainment. We’ll look at the trade-offs and benefits of each case
separately.

Entertainment

In entertainment there are three possible uses, maybe more: watching movies, editing video or photos, and game playing. For this issue of Tech Watch, we’ll look at game playing and will review watching movies and video/photo editing in a future issue.

First off, let me say looking at a favorite game for the first time with 55 x 21-inches of screen space and 5760 x 2160 resolution is simply thrilling. There is truly nothing like it. And when you are playing cinematic big story games you really are in the movies. But, there are trade-offs. Some (maybe most) games have a preamble video. Often it is used for benchmarking, if the game engine was used to render the video. However, the developers never anticipated such screen sizes and so the video, machinema, etc., is not scaled to full screen and so the opening scenes fall to one screen, typically the lower middle one. Some of the videos will scale a little to the available lines and fill 2/3rd of the bottom of the top middle screen and 2/3s of the top of the bottom middle screen. This is not a pleasant way to watch the videos because of the distortions of the scaling (not really sure which engine is doing the scaling—the game engine or the video scaler on the AIB, but suspect it is the game engine).

POV in a FPS

If you take full advantage of the six displays, the point of view (POV) of the gun sight in a first-person shooter will fall right in the middle of the bezels between the two middle screens. You can play the game this way, but it’s difficult, you can’t fire very fast because you are unsure of where the target really is.

I tried to find tweaks in the setup and .ini files to offset the sight with no success. However, I found a suitable compromise. In Stalker I was able to set it up so it didn’t run in full resolution of the screens and set the game resolution to 4800 x 1800, this gives you 83% of the image size and resolution as the full screen 3x2. Also, I set the desktop background to black so you get one large bezel to the right and bottom, and visible gun sights with pretty high resolution.

Not all games offer these intermediate resolutions. Some, especially the games ported from consoles like Bio Shock 2, and Battlefield: Bad Company 2, will fill to the resolution available—there is no adjustment.

3x2 not ideal

Because of the POV issue and the variances between games and tier options for resolution setting, a landscape 3x2 configuration isn’t the best choice, although it certainly is the most impressive. Our experiments indicate a 3x1 in landscape is better for FPSs. A 5x1 in portrait is the ideal solution for POV and maximum resolution in a FPS (Table 3).

Comparing the 5x1 to a 3x2 the ratios look quite acceptable (Table 4).

We’re still wrestling this configuration so there’s no photo to illustrate it. We’ll have that in the next issue.

An odd number of displays puts the POV right in the center of the middle display. And setting the displays in portrait mode gives the maximum vertical resolution. Mounting the displays and getting them physically aligned is the major issue.

Wrapping vs. wall

Another physical issue is the horizontal placement of the displays. Although it’s very impressive to see a video wall layout of six monitors, in practice it’s not very convenient to use them that way. We have found turning the left and the right monitors outward (toward the user) by about 30 degrees, gives a much better, and more natural feeling.

Part of this is due to the way perspective is set up in the game engine. Some games will allow adjustment of the perspective. With exaggerated perspective (which is normal for games) an angle toward the viewer setup gives the best visual results.

Seeing double

The next logical step in this development (for ATI) will be to run S3D. That will require three to six 120 Hz monitors and some frame buffer management work on ATI’s part. Because of the need to generate two images two AIBs may be needed.

Productivity

Using multiple displays for productivity creates a whole different set of issues. In this case you want as much screen real-estate as possible, and a 3x2 is an ideal choice.

And of course, one of the applications opened can be a game, set to a single screen’s resolution. (Admittedly, this begs the question of how productive you are really planning to be, but the situation does come up from time to time.)

The game will always default to the upper right hand corner.