I have two 27" monitors with a 2560 x 1920 resolution each. When I try to extend my desktop across them both I get the below error:

enter image description here

So, if I need to increase the maximum virtual screen size? To include a resolution of 5120 x 1920.

I've been trying to do this for about 12 hours now....

I have tried using xrandr arandr and a bunch of other tools recommend on this site and other forums.

I have added a xorg.conf file to /etc/X11 (which didn't exist already, and I generated) which now looks like this:

Note: This is just a snippet from the file (I can post it if needed).

Section "Screen"
    SubSection "Display"
                Virtual 5120 4096

I also tried a bunch of other similar answers, and in the process messed up the xorg server and wasn't able to boot at all until re installing it.

I know xserver changed a bit from 12 to 14, and now uses a bunch of files in /usr/share/xorg.conf.d, which I have also played around with. My understanding is putting a xorg.conf file in the /etc/X11 folder would overrule that anyway (but really, I've been trying anything).

So far nothing has worked.

Some things have had an effect, like me not being able to boot up at all, or get past the logo, which have been solved by root terminalling in safe mode to undo changes or reinstall xserver.

Any ideas would be appreciated.

  • Take a look at thinkwiki.org/wiki/Xorg_RandR_1.2#the_Virtual_screen for an explanation of why 4096x4096 is the limit. – James Oct 12 '14 at 14:21
  • Thanks @James I hadn't seen that. It doesn't really explain why 4096 4096 is the limit, just that it is, and the higher the number the more resources are consumed. tl;dr: Is there any way I can increase to 5120 1920? I really don't want to go back to windows.. – S.. Oct 12 '14 at 15:46
  • Also take a look at askubuntu.com/questions/347292/… for a possible workaround. – James Oct 13 '14 at 0:28
  • 'Sadly'I went back to windows for this machine.. It simply works. – S.. Nov 27 '14 at 11:44

xrandr --output VGA1 --rate 60 --mode 1440x900 --fb 5120x1920 --panning 5120x1920

where --rate xx and mode yyyyXyyy equal a valid mode for your monitor and the -fb and panning switches specify the desktop size. You'll have to adjust these values to your hardware. I don't have 2 monitors to test this so in your case I think you'd leave off the --panning switch and adjust your situation according to information here. This does result in a desktop of the desired size however and I can pan around it.

I returned my desktop to normal (for me) with xrandr --output VGA1 --rate 60 --mode 1440x900 --fb 1440x900

Tested under Lubuntu 14.04.4 64-bit

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