Debian/X.org notes - Intel driver 2.0 does not find my nice mode/resolution - Brice Goglin's Blog
Aug. 11th, 2007
13:21 - Debian/X.org notes - Intel driver 2.0 does not find my nice mode/resolution
The way to choose a resolution in xorg.conf changed with randr-1.2. With earlier X servers and drivers, you had a Mode option with a list of resolutions in your xorg.conf (and maybe some ModeLine options to choose the refresh rate). All this is almost useless nowadays with randr-1.2, you can drop all these options. The driver/server will detect all modes automatically and choose the preferred one (if the monitor says which one it prefers). The available modes for each outputs may be seen by running xrandr without arguments.
However, if there is no preferred mode or if it is not the one you want, you can change it for the currently running X server with the following command. Such a command may for instance be added to your .xsession file so that it is done every time you start the X server.
xrandr --output VGA --mode 1280x1024
But, it may also be done automatically through the server configuration. This is one of rare cases where ModeLine is still useful these days. Assuming you want to force 1280x1024 at 75Hz at startup, add something like the following to the Monitor section of your xorg.conf:
Modeline "1280x1024_75.00" 138.54 1280 1368 1504 1728 1024 1025 1028 1069 -HSync +Vsync Option "PreferredMode" "1280x1024_75.00"
The ModeLine line may be obtained by looking at your current Xorg.0.log if the mode is already detected (when it appears in the output of xrandr). Or you may generate a new one using:
$ gtf 1280 1024 75 Modeline "1280x1024_75.00" 138.54 1280 1368 1504 1728 1024 1025 1028 1069 -HSync +Vsync
See this bug for an example.