I'm running Ubuntu 18.04 with GNOME 3.28.2 on my work desktop, and cannot for the life of me get more than one display to work. It has a stock AMD Radeon pro wx2100 graphics card (my work is not GPU-intensive), which supports multiple monitors, as far as I can tell from researching it. Many of the suggestions I've seen on Google involve issues with NVIDIA cards, which shouldn't be my problem...
xrandr output (with both monitors plugged in):
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
DisplayPort-2 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 527mm x 296mm
1920x1080 60.00*+ 50.00 59.94
1680x1050 59.88
1280x1024 60.02
1440x900 59.90
1280x800 59.91
1152x864 75.00
1280x720 60.00 50.00 59.94
1024x768 70.07 60.00
800x600 60.32 56.25
720x576 50.00
720x480 60.00 59.94
640x480 66.67 60.00 59.95 59.94
720x400 70.08
Things I've tried:
- switching cables/ports: it has 3 DisplayPorts and 2 USB-C ports. I've tried every combination of DP to HDMI and USB-C to HDMI adapters we have in every port it has. It will recognize any one monitor with any cable or port, but will not recognize more than one. So, it doesn't seem to be my adapters, cables, or ports.
- reinstalling the AMD driver
- switching from GDM3 to LightDM, unplugging the second monitor, rebooting, and plugging it back in
- updating the drivers through
sudo ubuntu-drivers autoinstall
I've seen a suggestion to run X11 as root on this thread: External monitor not detected on Ubuntu 18.04,
but I'm a little hesitant to start altering files since I don't completely understand what I'm doing. All my data is backed up, but there's so much of it (and I use so much finicky software) that it would be a huge pain to get everything set back up if I ended up needing to reinstall Ubuntu because I broke something.
