Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 11-05-2007 Installation Manual page 504

The last line of the Display subsection with Depth 16 refers to the size of
the virtual screen. The maximum possible size of a virtual screen depends on the
amount of memory installed on the graphics card and the desired color depth, not
on the maximum resolution of the monitor. Because modern graphics cards have
a large amount of video memory, you can create very large virtual desktops.
However, you may no longer be able to use 3D functionality if you fill most of
the video memory with a virtual desktop. If the card has 16 MB video RAM, for
example, the virtual screen can be up to 4096x4096 pixels in size at 8-bit color
depth. Especially for accelerated cards, however, it is not recommended to use
all your memory for the virtual screen, because this memory on the card is also
used for several font and graphics caches.
The Identifier line (here Screen[0]) gives this section a defined name
with which it can be uniquely referenced in the following ServerLayout sec-
tion. The lines Device and Monitor specify the graphics card and the monitor
that belong to this definition. These are just links to the Device and Monitor
sections with their corresponding names or identifiers. These sections are discussed
in detail below.
26.1.2 Device Section
A device section describes a specific graphics card. You can have as many device entries
in xorg.conf as you like, provided their names are differentiated using the keyword
Identifier. If you have more than one graphics card installed, the sections are
simply numbered in order. The first one is called Device[0], the second one
Device[1], and so on. The following file shows an excerpt from the Device section
of a computer with a Matrox Millennium PCI graphics card (as configured by SaX2):
Section "Device"
BoardName
BusID
Driver
Identifier
VendorName
Option
EndSection
The BusID defines the PCI or AGP slot in which the graphics card is installed.
This matches the ID displayed by the command lspci. The X server needs details
486 Installation and Administration
"MGA2064W"
"0:19:0"
"mga"
"Device[0]"
"Matrox"
"sw_cursor"