Dual Monitors on 18.04 with Radeon RX 580 GPU

I recently installed 18.04 and seemed well. The system detected both monitors I have and all was fine. 2 days ago my screens went blank suddenly, not waking up from a few key presses or a wiggle of the mouse, I rebooted the machine. Now Ubuntu is only on one of these monitors. I performed a fresh install but the issue still persists. I have also downloaded and installed the latest AMD GPU driver from and no change. (slight change in that now I get a very slight flicker now and again)

This particular machine is dual boot with Windows 10 and that performs fine - detecting both monitors. Even the BIOS displays over two screens so am pretty sure this isn't hardware related.

I'm not looking for 3D acceleration or anything on my Ubuntu partition - just two monitors for working.

This kind of thing really is beyond me but some output from some various commands:

lspci -nnk | grep -i vga -A3 | grep 'in use' Kernel driver in use: amdgpu
sudo lshw -c video *-display description: VGA compatible controller product: Ellesmere [Radeon RX 470/480/570/570X/580/580X] vendor: Advanced Micro Devices, Inc. [AMD/ATI] physical id: 0 bus info: pci@0000:25:00.0 version: e7 width: 64 bits clock: 33MHz capabilities: pm pciexpress msi vga_controller bus_master cap_list rom configuration: driver=amdgpu latency=0 resources: irq:47 memory:e0000000-efffffff memory:f0000000-f01fffff ioport:f000(size=256) memory:fe900000-fe93ffff memory:c0000-dffff
xrandr
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)
HDMI-A-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 531mm x 299mm 1920x1080 60.00*+ 50.00 59.94 1600x1200 60.00 1680x1050 59.88 1280x1024 60.02 1440x900 59.90 1280x960 60.00 1280x800 60.00 1280x720 60.00 50.00 59.94 1152x720 59.97 1024x768 60.00 800x600 60.32 56.25 720x576 50.00 720x480 60.00 59.94 640x480 66.67 60.00 59.94
HDMI-A-1 disconnected (normal left inverted right x axis y axis) 1920x1080 60.00
DVI-D-0 disconnected (normal left inverted right x axis y axis)

Any help or guidance would be massively appreciated!

1 Answer

Based on the @dobey ansewer:

1. Run sudo nano /etc/default/grub
2. Change GRUB_CMDLINE_LINUX_DEFAULT and save:

GRUB_CMDLINE_LINUX_DEFAULT="splash amdgpu.dc=0"

3. Run sudo update-grub
4. Reboot your system