How to configure settings for unknown monitor?
When I have unknown monitor connected, how can I increase resolution to match device connected?
When monitor correctly communicates with the graphics card and system the modes supported will correctly appear and monitor will correctly be configured. In current linux distros hardware settings for x-server are by default done without use of configuration file. After attaching a new monitor we can configure it automatically just by switching to terminal and back to graphics terminal to softly restart the xserver e.g. (Ctrl-Alt-F1), (Ctrl-Alt-F8). A better way it probably to use the monitor preferences command in the start menu (Found in gnome start menu under System>Preferences>Monitors). However if supported modes are not found then there is a useful command line tool we can use to add the supported mode to xserver.
In my case after attaching “gateway” monitor to my lenovo t410 laptop by VGA shaped port only the following resolutions were available. If software configuration is not possible then a hardware solution is to select 1:1 video scaling in menu of the monitor to prevent smearing of pixels.
Available resolutions for unknown monitor:
I found following example::
Screen 0: minimum 320 x 200, current 1368 x 768, maximum 8192 x 8192
VGA1 connected 1368×768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
800×600 60.3 56.2
$ cvt 1440 900
$ xrandr –newmode “1440x900_60.00″ 106.50 1440 1528 1672 1904 900 903 909 934 -hsync +vsync
$ xrandr –addmode VGA1 1440x900_60.00
I issued following commands to add support of my monitor::
We want to add a mode to support the resolution of external monitor which in this case is 1680×1050. If we issue “cvt” command we will be informed of the correct “modeline” options we need to issue with “xrandr”.
>cvt 1680 1050
# 1680×1050 59.95 Hz (CVT 1.76MA) hsync: 65.29 kHz; pclk: 146.25 MHz
Modeline “1680x1050_60.00″ 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync
xrandr –newmode “1680x1050_60.00″ 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync
xrandr –addmode VGA-1 1680x1050_60.00
After issuing the final command we can select the mode of the monitor (and select relative position etc, etc) using the “monitor preferences” tool. Found in gnome start menu under System>Preferences>Monitors. This tool can be added to the start panel if desired.
alternative tools exist, e.g. grandr is another graphical tool to see monitor settings.