Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 04-08-2006 Installation Manual page 501

number pad), switch to the left. This enables you to vary the resolution while X is run-
ning.
The last line of the Display subsection with Depth 16 refers to the size of the vir-
tual 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.
27.2.2 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. As a rule—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:
Section "Device"
BoardName "MGA2064W"
BusID "0:19:0"
Driver "mga"
Identifier "Device[0]"
VendorName "Matrox"
Option "sw_cursor"
EndSection
If you use SaX2 for configuration, the device section should look something like the
above example. Both the Driver and BusID are dependent on the hardware installed
in your computer and are detected by SaX2 automatically. 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 in decimal form, but lspci displays these
in hexadecimal form.
Wit the Driver parameter, specify the driver to use for this graphics card. If the card
is a Matrox Millennium, the driver module is called mga. The X server then searches
The X Window System 501