Lines to Delete:
MergedFB
CRT2HSync
CRT2VRefresh
MergedXinerama
MetaModes
CRT2Position
Enabled
TwinView
Examining the file that controls display: man xorg.conf
MergedFB
CRT2HSync
CRT2VRefresh
MergedXinerama
MetaModes
CRT2Position
Enabled
TwinView
Examining the file that controls display: man xorg.conf
Examining the file that controls display: man xorg.conf
My video card:
VGA compatible controller: ATI Technologies Inc RS400 [Radeon Xpress 200] (prog-if 00 [VGA controller])
Subsystem: ASUSTeK Computer Inc. Device 81c8
Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 17
Memory at d8000000 (32-bit, prefetchable) [size=128M]
I/O ports at ee00 [size=256]
Memory at fddf0000 (32-bit, non-prefetchable) [size=64K]
[virtual] Expansion ROM at fdd00000 [disabled] [size=128K]
Capabilities: [50] Power Management version 2
Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
Kernel driver in use: radeon
Kernel modules: radeon
Xorg.conf Possible Locations:
/etc/X11/<cmdline>
/usr/etc/X11/<cmdline>
/etc/X11/$XORGCONFIG
/usr/etc/X11/$XORGCONFIG
/etc/X11/xorg.conf
/etc/xorg.conf
/usr/etc/X11/xorg.conf.<hostname>
/usr/etc/X11/xorg.conf
/usr/lib/X11/xorg.conf.<hostname>
/usr/lib/X11/xorg.conf
the /etc/X11/xorg.conf file is no longer created by default.
You can create one and add your configuration to it if you wish to.
You can create one and add your configuration to it if you wish to.
The xorg.conf and xorg.conf.d files are composed of a number of sections which may be present in
any order, or omitted to use default configuration values. Each section has the form:
Section "SectionName"
SectionEntry
...
EndSection
The section names are:
Files File pathnames
ServerFlags Server flags
Module Dynamic module loading
Extensions Extension enabling
InputDevice Input device description
InputClass Input class description
Device Graphics device description
VideoAdaptor Xv video adaptor description
Monitor Monitor description
Modes Video modes descriptions
Screen Screen configuration
ServerLayout Overall layout
DRI DRI-specific configuration
Vendor Vendor-specific configuration
Monitor Information:
MONITOR SECTION
The config file may have multiple Monitor sections. There should normally be at least one, for
the monitor being used, but a default configuration will be created when one isn't specified.
Monitor sections have the following format:
Section "Monitor"
Identifier "name"
entries
...
EndSection
The only mandatory entry in a Monitor section is the Identifier entry.
The Identifier entry specifies the unique name for this monitor. The Monitor section may be used
to provide information about the specifications of the monitor, monitor-specific Options, and
information about the video modes to use with the monitor.
With RandR 1.2-enabled drivers, monitor sections may be tied to specific outputs of the video
card. Using the name of the output defined by the video driver plus the identifier of a monitor
section, one associates a monitor section with an output by adding an option to the Device section
in the following format:
Option "Monitor-outputname" "monitorsection"
(for example, Option "Monitor-VGA" "VGA monitor" for a VGA output)
In the absence of specific association of monitor sections to outputs, if a monitor section is
present the server will associate it with an output to preserve compatibility for previous single-
head configurations.
Specifying video modes is optional because the server will use the DDC or other information pro‐
vided by the monitor to automatically configure the list of modes available. When modes are spec‐
ified explicitly in the Monitor section (with the Modes, ModeLine, or UseModes keywords), built-in
modes with the same names are not included. Built-in modes with different names are, however,
still implicitly included, when they meet the requirements of the monitor.
The entries that may be used in Monitor sections are described below.
VendorName "vendor"
This optional entry specifies the monitor's manufacturer.
ModelName "model"
This optional entry specifies the monitor's model.
HorizSync horizsync-range
gives the range(s) of horizontal sync frequencies supported by the monitor.
horizsync-range may be a comma separated list of either discrete values or ranges of val‐ ues. A range of values is two values separated by a dash. By default the values are in
units of kHz. They may be specified in MHz or Hz if MHz or Hz is added to the end of the
line. The data given here is used by the Xorg server to determine if video modes are
within the specifications of the monitor. This information should be available in the mon‐
itor's handbook. If this entry is omitted, a default range of 28-33kHz is used.
VertRefresh vertrefresh-range
gives the range(s) of vertical refresh frequencies supported by the monitor. vertre‐
fresh-range may be a comma separated list of either discrete values or ranges of values. A
range of values is two values separated by a dash. By default the values are in units of
Hz. They may be specified in MHz or kHz if MHz or kHz is added to the end of the line.
The data given here is used by the Xorg server to determine if video modes are within the
specifications of the monitor. This information should be available in the monitor's hand‐
book. If this entry is omitted, a default range of 43-72Hz is used.
DisplaySize width height
This optional entry gives the width and height, in millimetres, of the picture area of the
monitor. If given this is used to calculate the horizontal and vertical pitch (DPI) of the
screen.
Gamma gamma-value
Gamma red-gamma green-gamma blue-gamma
This is an optional entry that can be used to specify the gamma correction for the monitor.
It may be specified as either a single value or as three separate RGB values. The values
should be in the range 0.1 to 10.0, and the default is 1.0. Not all drivers are capable of
using this information.
UseModes "modesection-id"
Include the set of modes listed in the Modes section called modesection-id. This makes all
of the modes defined in that section available for use by this monitor.
Mode "name"
This is an optional multi-line entry that can be used to provide definitions for video
modes for the monitor. In most cases this isn't necessary because the built-in set of VESA
standard modes will be sufficient. The Mode keyword indicates the start of a multi-line
video mode description. The mode description is terminated with the EndMode keyword. The
mode description consists of the following entries:
DotClock clock
is the dot (pixel) clock rate to be used for the mode.
HTimings hdisp hsyncstart hsyncend htotal
specifies the horizontal timings for the mode.
VTimings vdisp vsyncstart vsyncend vtotal
specifies the vertical timings for the mode.
Flags "flag" ...
specifies an optional set of mode flags, each of which is a separate string in double
quotes. "Interlace" indicates that the mode is interlaced. "DoubleScan" indicates a
mode where each scanline is doubled. "+HSync" and "-HSync" can be used to select the
polarity of the HSync signal. "+VSync" and "-VSync" can be used to select the polarity
of the VSync signal. "Composite" can be used to specify composite sync on hardware
where this is supported. Additionally, on some hardware, "+CSync" and "-CSync" may be
used to select the composite sync polarity.
HSkew hskew
specifies the number of pixels (towards the right edge of the screen) by which the dis‐
play enable signal is to be skewed. Not all drivers use this information. This option
might become necessary to override the default value supplied by the server (if any).
“Roving” horizontal lines indicate this value needs to be increased. If the last few
pixels on a scan line appear on the left of the screen, this value should be decreased.
VScan vscan
specifies the number of times each scanline is painted on the screen. Not all drivers
use this information. Values less than 1 are treated as 1, which is the default. Gen‐
erally, the "DoubleScan" Flag mentioned above doubles this value.
ModeLine "name" mode-description
This entry is a more compact version of the Mode entry, and it also can be used to specify
video modes for the monitor. is a single line format for specifying video modes. In most
cases this isn't necessary because the built-in set of VESA standard modes will be suffi‐
cient.
The mode-description is in four sections, the first three of which are mandatory. The
first is the dot (pixel) clock. This is a single number specifying the pixel clock rate
for the mode in MHz. The second section is a list of four numbers specifying the horizon‐
tal timings. These numbers are the hdisp, hsyncstart, hsyncend, and htotal values. The
third section is a list of four numbers specifying the vertical timings. These numbers are
the vdisp, vsyncstart, vsyncend, and vtotal values. The final section is a list of flags
tal timings. These numbers are the hdisp, hsyncstart, hsyncend, and htotal values. The
third section is a list of four numbers specifying the vertical timings. These numbers are
the vdisp, vsyncstart, vsyncend, and vtotal values. The final section is a list of flags
specifying other characteristics of the mode. Interlace indicates that the mode is inter‐
laced. DoubleScan indicates a mode where each scanline is doubled. +HSync and -HSync can
be used to select the polarity of the HSync signal. +VSync and -VSync can be used to
select the polarity of the VSync signal. Composite can be used to specify composite sync
on hardware where this is supported. Additionally, on some hardware, +CSync and -CSync may
be used to select the composite sync polarity. The HSkew and VScan options mentioned above
in the Modes entry description can also be used here.
Option "DPMS" "bool"
This option controls whether the server should enable the DPMS extension for power manage‐
ment for this screen. The default is to enable the extension.
Option "SyncOnGreen" "bool"
This option controls whether the video card should drive the sync signal on the green color
pin. Not all cards support this option, and most monitors do not require it. The default
is off.
Option "Primary" "bool"
This optional entry specifies that the monitor should be treated as the primary monitor.
(RandR 1.2-supporting drivers only)
Option "PreferredMode" "string"
This optional entry specifies a mode to be marked as the preferred initial mode of the mon‐
itor. (RandR 1.2-supporting drivers only)
Option "Position" "x y"
This optional entry specifies the position of the monitor within the X screen. (RandR
1.2-supporting drivers only)
Option "LeftOf" "output"
This optional entry specifies that the monitor should be positioned to the left of the out‐
put (not monitor) of the given name. (RandR 1.2-supporting drivers only)
Option "RightOf" "output"
This optional entry specifies that the monitor should be positioned to the right of the
output (not monitor) of the given name. (RandR 1.2-supporting drivers only)
Option "Above" "output"
This optional entry specifies that the monitor should be positioned above the output (not
monitor) of the given name. (RandR 1.2-supporting drivers only)
Option "Below" "output"
This optional entry specifies that the monitor should be positioned below the output (not
monitor) of the given name. (RandR 1.2-supporting drivers only)
Option "Enable" "bool"
This optional entry specifies whether the monitor should be turned on at startup. By
default, the server will attempt to enable all connected monitors. (RandR 1.2-supporting
drivers only)
Option "DefaultModes" "bool"
This optional entry specifies whether the server should add supported default modes to the
list of modes offered on this monitor. By default, the server will add default modes; you
should only disable this if you can guarantee that EDID will be available at all times, or
if you have added custom modelines which the server can use. (RandR 1.2-supporting drivers
only)
Option "MinClock" "frequency"
This optional entry specifies the minimum dot clock, in kHz, that is supported by the moni‐
tor.
Option "MaxClock" "frequency"
This optional entry specifies the maximum dot clock, in kHz, that is supported by the moni‐
tor.
Option "Ignore" "bool"
This optional entry specifies that the monitor should be ignored entirely, and not reported
through RandR. This is useful if the hardware reports the presence of outputs that don't
exist. (RandR 1.2-supporting drivers only)
Option "Rotate" "rotation"
This optional entry specifies the initial rotation of the given monitor. Valid values for
rotation are "normal", "left", "right", and "inverted". (RandR 1.2-supporting drivers
only)
SCREEN SECTION
The config file may have multiple Screen sections. There must be at least one, for the “screen”
being used. A “screen” represents the binding of a graphics device (Device section) and a monitor
(Monitor section). A Screen section is considered “active” if it is referenced by an active
ServerLayout section or by the -screen command line option. If neither of those is present, the
first Screen section found in the config file is considered the active one.
Screen sections have the following format:
Section "Screen"
Identifier "name"
Device "devid"
Monitor "monid"
entries
...
SubSection "Display"
entries
...
EndSubSection
...
EndSection
The Identifier and Device entries are mandatory. All others are optional.
The Identifier entry specifies the unique name for this screen. The Screen section provides
information specific to the whole screen, including screen-specific Options. In multi-head con‐
figurations, there will be multiple active Screen sections, one for each head. The entries avail‐
able for this section are:
Device "device-id"
This mandatory entry specifies the Device section to be used for this screen. This is what
ties a specific graphics card to a screen. The device-id must match the Identifier of a
Device section in the config file.
Monitor "monitor-id"
specifies which monitor description is to be used for this screen. If a Monitor name is
not specified, a default configuration is used. Currently the default configuration may
not function as expected on all platforms.
VideoAdaptor "xv-id"
specifies an optional Xv video adaptor description to be used with this screen.
DefaultDepth depth
specifies which color depth the server should use by default. The -depth command line
option can be used to override this. If neither is specified, the default depth is
driver-specific, but in most cases is 8.
DefaultFbBpp bpp
specifies which framebuffer layout to use by default. The -fbbpp command line option can
be used to override this. In most cases the driver will chose the best default value for
this. The only case where there is even a choice in this value is for depth 24, where some
hardware supports both a packed 24 bit framebuffer layout and a sparse 32 bit framebuffer Options
Various Option flags may be specified in the Screen section. Some are driver-specific and
are described in the driver documentation. Others are driver-independent, and will eventu‐
ally be described here.
Option "Accel"
Enables XAA (X Acceleration Architecture), a mechanism that makes video cards' 2D hardware
acceleration available to the Xorg server. This option is on by default, but it may be
necessary to turn it off if there are bugs in the driver. There are many options to dis‐
able specific accelerated operations, listed below. Note that disabling an operation will
have no effect if the operation is not accelerated (whether due to lack of support in the
hardware or in the driver).
Option "InitPrimary" "boolean"
Use the Int10 module to initialize the primary graphics card. Normally, only secondary
cards are soft-booted using the Int10 module, as the primary card has already been initial‐
ized by the BIOS at boot time. Default: false.
Option "NoInt10" "boolean"
Disables the Int10 module, a module that uses the int10 call to the BIOS of the graphics
card to initialize it. Default: false.
Option "NoMTRR"
Disables MTRR (Memory Type Range Register) support, a feature of modern processors which
can improve video performance by a factor of up to 2.5. Some hardware has buggy MTRR sup‐
port, and some video drivers have been known to exhibit problems when MTRR's are used.
Options
Various Option flags may be specified in the Screen section. Some are driver-specific and
are described in the driver documentation. Others are driver-independent, and will eventu‐
ally be described here.
Option "Accel"
Enables XAA (X Acceleration Architecture), a mechanism that makes video cards' 2D hardware
acceleration available to the Xorg server. This option is on by default, but it may be
necessary to turn it off if there are bugs in the driver. There are many options to dis‐
able specific accelerated operations, listed below. Note that disabling an operation will
have no effect if the operation is not accelerated (whether due to lack of support in the
hardware or in the driver).
Option "InitPrimary" "boolean"
Use the Int10 module to initialize the primary graphics card. Normally, only secondary
cards are soft-booted using the Int10 module, as the primary card has already been initial‐
ized by the BIOS at boot time. Default: false.
Option "NoInt10" "boolean"
Disables the Int10 module, a module that uses the int10 call to the BIOS of the graphics
card to initialize it. Default: false.
Option "NoMTRR"
Disables MTRR (Memory Type Range Register) support, a feature of modern processors which
can improve video performance by a factor of up to 2.5. Some hardware has buggy MTRR sup‐
port, and some video drivers have been known to exhibit problems when MTRR's are used.
