Xrandr failed to get size of gamma for output under Linux – that is the reason
This error usually occurs when you want to assign, for example, a screen, a new profile with a different screen resolution.
- The new profile will be created with "xrandr --newmode".
- A common error here is "sudo" prefix. Thus, the profile with administrative Rights is created.
- So it comes the error message "Xrandr failed to get size of gamma for output".
Screen resolution with Xrandr to change on Linux
A new resolution profile and add your screen as follows.
- Calculate the later, the required settings with the command cvt 1200 1000 60.
- Here's a profile with the resolution of 1200x1000 and 60 Hz is calculated. The output should then look something like this: # 1200x1000 59.91 Hz (CVT) hsync: 62.19 kHz; pclk: 99.50 MHz Modeline "1200x1000_60.00" 99.50 1200 1280 1400 1600 1000 1003 1013 1038 -hsync +vsync.
- The second line of the output type in the next command, with which you create the profile: xrandr --newmode "1200_1000_60" 99.50 1200 1280 1400 1600 1000 1003 1013 1038 -hsync +vsync.
- Connect add the profile to the screen to add: xrandr --addmode 1200x1000_60.00.
- Here you replace with the type of port your monitor is connected. Usual values VGA1, DP1 or HDMI1 are. To your connection type to find out, type "xrandr" in your Terminal.
Failed to get size of gamma for output default is an error message when you Configure the screen under Linux
(Image: Screenshot)
