Wall Display Systemsusing

Linux or Solarisand theX Window System
Xi Graphics Has The Graphics System Software
With the recent addition of the new WallDisplay (HX) Series to the Summit Series of X servers and graphics
driver products, Xi Graphics has greatly expanded the Wall Display capabilities of its "X graphics" software productline. The HX Series complements the Multi-head (MX) Series introduced with the Summit Series in 2001. Together,
the MX and HX Series offer a wide range of capabilities for wall or console mounted monitors. Some features arecommon to both Series, while other features are offered in only one or the other.
Probably the most important feature common to both Series is that they are based on Xi Graphics' Accelerated-XÙ
implementation of the industry-standard X Window System ("X") for UNIX. Summit Series code is high-quality,commercial software, developed by Xi Graphics for users who need stable, high performance graphics, backed byrapid, competent customer support. Accelerated-X is architected and implemented "from scratch" by Xi Graphics
for use with open source Linux and other UNIX kernels.

HX Series Key Features

MX Series Key Features

Ô Single Logical Screen (across multiple chips)
Ô Multiple Xscreens per Chip AllowedÔ Mixed SLS and Multi-screen Allowed (some limitations)ÔAll Xscreens & Monitor Outputs Hardware Accelerated
Ô Powerful, Simple Graphical Configurator
Ô "Hidden Pixel" CapabilityÔ Pixel "Voids" Capability
Ô Mixed Monitor Resolutions (some limitations)Ô Rotate (any, all monitors) Option (some limitations)Ô "T" & "L" Monitor Configurations AllowedÔ Cursor Wrap, non-Wrap Controls
Ô PCIe & 64-bit Platform Capability
Ô Image Overlay Support
Ô XVideo Input Support

Ô Multiple Cards/Chips
Ô Multiple Xscreens per Chip AllowedÔ SLS per Chip AllowedÔ Mixed SLS and Multi-screen Allowed (some limitations)ÔAll Xscreens & Monitor Outputs Hardware Accelerated
Ô OpenGL SLS Capability (some limitations)Ô Powerful, Simple Graphical Configurator
Ô Rotate (any, all monitors) Option (some limitations)Ô Mixed Monitor Resolutions Allowed (some limitations)Ô Cursor Wrap, non-Wrap Controls
Ô PCIe & 64-bit Platform Capability
Ô Image Overlay Support
Ô XVideo Input Support

Accelerated-X Means Quality

Move From Windows to "X"

Software intelligently designed, skillfully implemented,
thoroughly tested, and supported by the group that did it.
Xi Graphics has developed and licensed Accelerated-X
graphics software - X servers and graphics drivers for overten years to industry and individuals for use on hundredsof different models of graphics cards/chips running on
various operating systems - including open source Linuxkernels - and computer platforms when fast, stable, andMicrosoft Windows and the X Window System are very
different animals, graphically speaking. The six-monitor
display depicted below is displaying a single image that is"stretched" across all six monitors - standard with MS
Windows. With X, the standard basically assumes thateach monitor (head) will have its own xscreen. To provide
X with the capability to stretch a single xscreen acrossmultiple graphics cards/chips while employing hardwareacceleration on all monitors for fast performance, requires

152x1141024x768
Figure 1. Single Logical Screen (w/o "hidden pixels")trouble-free performance is required. The Accelerated-X
Summit Series software is used in countless applications,
including mission critical ones such as Air Traffic Control
and Medical systems.

Quality Software, Quality Service
The X Window System software is a very large body ofvery sophisticated software that operates between an OS
kernel and applications software ("clients") to control("drive") the graphics hardware in a computer system.
Whereas X servers and graphics drivers provided to theLinux distributions by the "freeware community" have been
generated by many "contributors" of varying levels ofexpertise and are often lacking in performance stability
and follow-on service, the Summit Series software is
supported by the organization that originally developed it.
And that support is free, which means the original work
has to be of high quality, or the support load would breakthat the graphics sub-system (the X server, graphics
driver(s) and kernel interface driver) all be specificallydesigned and implemented to accomplish this. It is notthere "by default." And it is a major piece of engineering
effort to do it (SingleLogicalScreen) right.

Accelerated-X Does it Right
One of the ways to observe the difference between X.org X
servers and high-quality, high-performance commercial X
servers (such as Summit WallDisplay HX Series) is bycomparing a Wall Display with several - 6, 8, or even16
displays - operating with a single xscreen. Summit HX
Series will be fast, stable, easy to install/configure, featurerich, whether on Linux, Solaris, x86 or SPARC platforms,and will supported by the the same group that developed it.
Support is seldom required. It too is commercial quality,and, as we have said elsewhere, it is free.
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Key Features"HiddenPixels" Feature

Mixing Monitor Resolutions

The large graphic on the first page illustrates the idea ofhidden pixels in a multi-monitor display. Notice how thetext in the banner seems to be on the "other side" of thepanel frames. There are image pixels behind theframework, but they are "blocked" by the framing, giving
the impression of looking through a mult-pane picture
window. The more typical configuration is to have all
image pixels displayed, offset at the boundaries of themonitors, as shown in Figure 1. Both configurations areavailable in Summit HX Series.

An example of a multi-monitor configuration with mixed
resolutions that has one xscreen stretched over threemonitors and a second xscreen servicing a fourthmonitor is shown is Figure 2. In this case, the topmonitor of the "inverted T" configuration has a different
resolution than the other three. The cursor can travel
over all four monitors, with or without wraparound.
Support for such configurations is available in the HX
Series, and, with some limitations, also in the MX Series.

Large Pix Maps Can
Ruin Your Day
One of the severe limitations inX.org/XFree86 X servers is thepoor handling of pix maps, esp.
large ones. Application andGUI developers often are
unaware of the processing loadcaused by liberal use of pixmaps. With multi-card/chipsystems, this can result in very
poor system performance with

2560x1600

1024x768

1024x768

1024x768

Figure 2. "Inverted T" Configuration w/Res Mix

the open source freeware X servers. The design of theSummit WallDisplay HX Series included special
attention to this problem, and sophisticated methods tomaintain high performance while using pix maps weredeveloped. This high performance design is now usedin Summit Custom (CX) products for Air Traffic Control
applications that may also require real-time recording of
the graphics sub-system activities for later replay.
Because of the larger (and growing) size of the display
real estate being deployed in new ATC systems, thiswas no small feat, and one that no other Linux/UNIXAll Displays Hardware Accelerated
A complaint often heard when X.or/XFree86 X servers
are used in multi-card/chip Wall Display systems is theinability to get full hardware acceleration on all monitor
displays. This complaint is never lodged against
Accelerated-X, since all monitor displays are hardware
accelerated. Yes, even if there are 16 or more (thestandard HX product supports up to sixteen monitors the "Level 3" case - but support for up to 32 monitors isavailable as an option).
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Rotation - Low cost Portrait Mode

Linux is Popular, Solaris is Solid

Software image rotation in X can save big bucks byavoiding the cost of monitors designed for portrait mode
operation. With X.org/XFree86-based graphics systems,
however, the performance hit when using image rotation,is quite large, especially with large and/or multiple
monitors, sometimes large enough to make the feature
unusable. This is the result of a poorly designed X
server base to begin with, and when the additionalgraphics processing loadrequired by rotation isadded, the system justcannot cope.
2560x1600

Again, these are two very different animals. Linux is akernel from the Linux group. Other (loosely associated)groups put out the X.org/XFree86 open source X
servers/drivers that are used with the (many) Linuxkernels. The X server/driver code one gets with a
Solaris kernel is generally Sun Microsystems code,
which is coherent, well designed and tested by Sun.
Solaris has a reputation as code done by "grownups,"

Xi Graphics' HX Series
does not suffer from thedeficiencies of the open
source X servers/drivers,
since none of code isused in Accelerated-X.
Instead, Xi Graphics' X
graphics sub-system codeis all commercial code,
designed by a highly
skilled group ofdevelopers working at one
location for one company.
And the results are quite
2560x1600
impressive. The added
load of performing therotation is handled withease, causing only a slight
reduction in performance,even with large graphics
real estate, such as that shown at the right - two 30"
Apple Cinemas running on a Matrox RG200 remote
graphics box. with dual Dual Link capability.

32- and 64-bit Platforms Supported
And not just the x86 architecture. Xi Graphics products
are also running on SPARC, PPC, and PA RISC
platforms. If an Accelerated-X code base runs on one
platform, porting to another is mostly routine. And
because the code is clean, commercial code, even theinevitable bugs are routine fixes. While most Wall
Display systems are run on x86 (using MS Windows),
systems using X are on x86, SPARC, and somePAÒRISC platforms.

2560x1600

2560x1600

probably because Solaris is apparently developed firstfor use with Sun's SPARC product line - a product line
targeted mostly at the large commercial accounts. Since
Sun's Solaris software is developed primarily for thepurpose of selling large amounts of Sun's premium
SPARC hardware, shoddy Solaris OS software would bea big problem.
On the other hand, Linux kernel software is not designed
to sell anything from the Linux group. Maybe thisaccounts for what appears to be a noticeable lack of
discipline in the design and distribution of the code? Infact, maybe the code distributed by the the open source
X.org/XFree86 crowd is so poor because they too are
not designing code for the purpose of selling anything(except, maybe, consulting time)? Maybe, though, it isbecause there are just too many "cooks in the broth." 4Unusual Configuration A
To illustrate some of the features available in the HX Series, a few unusual and/or overly complicatedexamples are presented. This first one is simple. It is a horizontal string of monitors side-by-side configured
with a single xscreen. The number of monitors in the string shown below is only seven, but could be any
number up to the HX Series horizontal pixel limit of 32,768, or 20 monitors if each monitor had a resolution of1600x1200. There is only one xscreen in use, so the entire display is a SingleLogicalScreen in this case,displaying a single image across all seven monitors. The display on all monitors is hardware accelerated.

Unusual Configuration B
This example is of a wall display of twelve monitors (could be many more) configured with four xscreens, twoof which stretch across multiple monitors. One SLS ("stretched desktop") xscreen has a (synchronous)
video window that is scaled up and is crossing monitor boundaries. An XVideo window assigned to anxscreen cannot be moved (dragged) to another xscreen, but can be moved about within its own xscreen.
There can be multiple video windows assigned to an xscreen. HX Series (Silver Edition) supports up to six
video windows per display (X server) if the underlying hardware is capable. Two of the xscreens are using
overlays image overlays. This configuration is an example of the power and flexibility of the HX Series.

5Unusual Configuration C
Making use of the Rotate feature, this configuration has two big Apple Cinemas and a couple of 1600x1200
monitors in showing a single xscreen. All monitors are hardware accelerated. Rotate is also full hardware
accelerated. While a photo used in this figure, the actual display would be a computer generated image,and could also have overlays and multiple video windows. If the application required, Record and Playback
could be used (it is an optional feature in the HX Siver Edition) with very small loss of performance becauseof the method of recording used. Instead of trying to record the images, Accelerated-X recording method
takes periodic snapshots and captures the incoming commands and data to the X server betweensnapshots mixed with timing markers. The commands and data are provided to the recording application ineither compressed or uncompressed format. On playback, the X server just recreates the image(s) thatwere created by the original incoming commands and data.

Note that there is a rectangular section of the SingleLogicalScreen display that is not shown. It is configured
as a "black hole." Applications could render to such a hole, but the result would not be displayed. Similarly,
if the cursor space is not properly configured, the cursor could be moved into the hole and "lost."
Configuring the territory for the cursor is easy, however, and black holes can be off limits to the cursor.

6Xi Graphics, Inc.

Xi Graphics, Inc., 1580 Logan Street, #550, Denver, CO 80203, www.xig.com, 800-946-7433

About Xi Graphics
Since its founding in 1994, Xi Graphics only business has been the development and licensingof X Window System graphics sub-systems software (X servers, graphics drivers, kernel
modules, and OpenGL rendering pipelines) for use with various UNIX® operating systems,
including the Linux kernel(s). Graphics support for nearly a thousand graphics cards/chips
models have been developed since that time, using confidential documentation provided by
the graphics card/chip manufacturers themselves under Non-Disclosure Agreements.
Xi Graphics software has earned a reputation for high performance in terms of speed, features, andstability. Customer support is provided free, usually by the developers themselves. This management
technique has the effect if insuring that the high quality standards of the Company are met before thesoftware is released, not many months or even years later.
Software is normally licensed in binary form only, and normally on a per computer basis. For
highly specialized or unusual situations, other arrangements may be available.

© Copyright 2009, Xi Graphics, Inc.

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