video - How to set custom screen resolution with xrandr (output - default)

  • dmdkv

    I need to set some fancy resolution, like 700x500, 320x860, 400x400 etc. The problem is that the output of the device is not recognized, so it's set to default. But when I add a newmode to xrandr it warns that "Failed to get size of gamma for output default". And after I add the new mode to default output, xrandr fails to set the new resolution, responding "Configure crtc 0 failed". How can I fix this issue?

  • Answers
  • Cougar

    Not every mode is possible. Here you can get nice example of some possible custom modelines. Still every modeline is not supported by every video card or monitor.

  • Related Question

    ubuntu - dual screens, xrandr: get names of video devices
  • Adam Matan

    I have been trying to configure dual-screen with my laptop docking station using xrandr.

    After some Google and SU searches, I have managed to:

    xrandr --output LVDS --pos 1680x0

    Which sets my laptop screen (LVDS) to be just at the right size of my desktop screen.

    Now, if I like to put it on the left side, I must use this notation:

    xrandr --output LVDS --left-of MY_DESKTOP_SCREEN

    Of course, there's no MY_DESKTOP_SCREEN device so I get:

    xrandr: cannot find output "MY_DESKTOP_SCREEN"

    How do I find or configure the names of my video devices?

  • Related Answers
  • 8088

    This site helped, so i typed:

    xrandr -q

    q stands for query, which gives:

    Screen 0: minimum 320 x 200, current 1680 x 1050, maximum 2960 x 1050
    VGA connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
       1680x1050      60.0*+   59.9
       1280x1024      75.0     59.9
       1280x960       59.9
       1152x864       75.0     74.8
       1024x768       75.1     70.1     60.0
       832x624        74.6
       800x600        72.2     75.0     60.3     56.2
       640x480        75.0     72.8     66.7     60.0
       720x400        70.1
    LVDS connected 1280x800+0+0 (normal left inverted right x axis y axis) 331mm x 207mm
       1280x800       60.2*+   60.0     50.0
       1280x768       60.0
       1024x768       60.0
       800x600        60.3
       640x480        59.9
    TV disconnected (normal left inverted right x axis y axis)

    Now I can:

    xrandr --output LVDS --left-of VGA


    And magic happens: