I'm running Ubuntu 13.04 and the max resolution it's letting me choose for the monitor I currently have plugged in - a 1280x1024 monitor - is 1024x768. The description for the Monitor is "Unknown". See attached:

Unknown monitor

The monitor is an IBM ThinkVision L170P.


From https://askubuntu.com/questions/139947/why-cant-ubuntu-12-04-detect-my-screen-resolution

Open your terminal and run this:

xrandr --newmode $(cvt 1280 1024 60 | grep Mode | sed -e 's/.*"/1280x1024/')
  • 6
    I had to do xrandr --addmode VGA1 1280x1024 as well but otherwise your solution worked! – neubert Dec 6 '13 at 7:04
  • 2
    xrandr --newmode $(cvt 1920 1080 60 | grep Mode | sed -e 's/.*"/1920x1080/') – atilkan Aug 21 '15 at 4:38
  • It worked, but why I have to run it every time the system starts? – Fahad Khan Oct 2 '15 at 5:18

First type xrandr -q to see your valid screen outputs eg. VGA1/DVI-1 etc...
Then xrandr --addmode DVI-1 1600x1200
Then new option will appear in your Displays configuration
Tested on ubuntu 14.04 and 2 screens ;)
note this change is not persistent after restart. To make it persistent I made shell script which do above mentioned command xrandr --addmode... and then I add line to file /etc/lightdm as follows


this way new resolution is added before desktop try to set it...

  • Just to add, make sure that "pathToYourScript" is executable. You can place it in /opt/ also. – M. Ahmad Zafar Mar 5 '16 at 7:58

Try installing mesa-utils using sudo apt-get install mesa-utils.

Once you have this installed reboot your machine. After rebooting the machine open a terminal and type glxinfo | grep render and glxgears

That should fix it.

  • I'm running Ubuntu LiveCD on this particular machine so that wouldn't work unfortunately :( – neubert Dec 6 '13 at 7:05
  • i don't think this is relevant. not working also. – atilkan Aug 21 '15 at 4:42

For 1920x1080 res 60 Hz use following:

xrandr --newmode $(cvt 1920 1080 60 | grep Mode | sed -e 's/.*"/1920x1080/')
xrandr --addmode VGA-1 1920x1080

One may encounter different output names: VGA1, VGA-1, etc.

More info HERE.

  • This appears to duplicate the accepted answer plus the OP's comment, only this version has the wrong resolution. – fixer1234 Nov 9 '18 at 9:03
  • The issue is that one comment mentiones VGA1 in addmode, in my case it's VGA-1 . And I have to get new resolution to work.It's just putting together nuances that may help others. – alex Nov 9 '18 at 15:16

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