C.3.3.8. The Screen section

Each Screen section binds one video card (or video card head) to one monitor by referencing the Device section and the Monitor section for each. While one Screen section is the minimum, additional instances may occur for each video card and monitor combination present on the machine.
The following example shows a typical Screen section: 
Section "Screen"
  Identifier "Screen0"
  Device "Videocard0"
  Monitor "Monitor0"
  DefaultDepth 16

  SubSection "Display"
    Depth 24
    Modes "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480"
  EndSubSection

  SubSection "Display"
    Depth 16
    Modes "1152x864" "1024x768" "800x600" "640x480"
  EndSubSection
EndSection
The following entries are commonly used in the Screen section:
  • Identifier — Specifies a unique name for this Screen section. This is a required entry.
  • Device — Specifies the unique name of a Device section. This is a required entry.
  • Monitor — Specifies the unique name of a Monitor section. This is only required if a specific Monitor section is defined in the xorg.conf file. Normally, monitors are detected automatically.
  • DefaultDepth — Specifies the default color depth in bits. In the previous example, 16 (which provides thousands of colors) is the default. Only one DefaultDepth entry is permitted, although this can be overridden with the Xorg command-line option -depth <n>, where <n> is any additional depth specified.
  • SubSection "Display" — Specifies the screen modes available at a particular color depth. The Screen section can have multiple Display subsections, which are entirely optional since screen modes are detected automatically.
    This subsection is normally used to override auto-detected modes.
  • Option "option-name" — An optional entry which specifies extra parameters for the section. Replace <option-name> with a valid option listed for this section in the xorg.conf(5) man page.