Installation guide

Chapter 6. The X Window System 99

Device

Speciﬁes information about the video card used by the system. You must have at least one De-

vice section in your conﬁguration ﬁle. You may have multiple Device sections in the case of

multiple video cards or multiple settings that can run a single card. The following options are

required or widely used:

• BusID — Speciﬁes the bus location of the video card. This option is only necessary for sys-

tems with multiple cards and must be set so that the Device section will use the proper settings

for the correct card.

• Driver — Tells XFree86 which driver to load in order to use the video card.

• Identifier — Provides a unique name for this video card. Usually, this name is set to the

exact name of the video card used in the Device section.

• Screen — An optional setting used when a video card has more than one head, or connector,

to go out to a separate monitor. If you have multiple monitors connected to one video card,

separate Device sections must exist for each of them with a different Screen value for each

Device section. The value accepted by this option is a number starting at 0 and increasing by

one for each head on the video card.

• VideoRam — The amount of RAM available on the video card in kilobytes. This setting is not

normally necessary since the XFree86 server can usually probe the video card to autodetect

the amount of video RAM. But since there are some video cards XFree86 cannot correctly

autodetect, this option allows you to specify the amount of video RAM.

DRI

Direct Rendering Infrastructure (DRI) is an interface which primarily allows 3D software ap-

plications to take advantage of the 3D hardware acceleration capabilities on modern supported

video hardware. In addition, DRI can improve 2D hardware acceleration performance when us-

ing drivers that have been enhanced to use the DRI for 2D operations. This section is ignored

unless DRI is enabled in the Module section.

Since different video cards use DRI in different ways. Before changing any DRI values, read the

/usr/X11R6/lib/X11/doc/README.DRI ﬁle for speciﬁc information about your particular

video card.

Files

This section sets paths for services vital to the XFree86 server, such as the font path. Common

options include:

• FontPath — Sets the locations where the XFree86 server can ﬁnd fonts. Different ﬁxed paths

to directories holding font ﬁles can be placed here, separated by commas. By default, Red

Hat Linux uses xfs as the font server and points FontPath to unix/:7100. This tells the

XFree86 server to obtain font information by using UNIX-domain sockets for inter-process

communication (IPC).

See Section 6.5 for more information concerning XFree86 and fonts.

• ModulePath — Allows you to set up multiple directories to use for storing modules loaded

by the XFree86 server.

• RgbPath — Tells the XFree86 server where the RGB color database is located on the system.

This database ﬁle deﬁnes all valid color names in XFree86 and ties them to speciﬁc RGB

values.