Second monitor goes blank after suspend or switch off/on the monitors

  • I have a Dual Monitor with two GeForce GTX 970 cards.

  • Ubuntu 20.04

  • The second monitor is never used by default by Ubuntu.

  • Finally I wrote a hand-made config file that uses the 2nd monitor when I log in and seems to works fine.

  • But if I suspend the computer or switch off the monitors, I lost the 2nd monitor (goes blank for ever) when resuming computer or switch on the monitors.

Please help me, I run this computer for large calculations and I don’t want to have the monitors actives for such large periods of time.

Thanks in advance.


Section “ServerLayout”
Identifier “Layout0”
Screen 0 “Screen0” 0 0
InputDevice “Keyboard0” “CoreKeyboard”
InputDevice “Mouse0” “CorePointer”
Option “Xinerama” “0”

Section “Files”

Section “InputDevice”
# generated from default
Identifier “Mouse0”
Driver “mouse”
Option “Protocol” “auto”
Option “Device” “/dev/psaux”
Option “Emulate3Buttons” “no”
Option “ZAxisMapping” “4 5”

Section “InputDevice”
# generated from default
Identifier “Keyboard0”
Driver “kbd”

Section “Monitor”
# HorizSync source: edid, VertRefresh source: edid
Identifier “Monitor0”
VendorName “Unknown”
ModelName “DELL P2715Q”
HorizSync 31.0 - 140.0
VertRefresh 29.0 - 75.0
Option “DPMS”

Section “Device”
Identifier “Device0”
Driver “nvidia”
VendorName “NVIDIA Corporation”
BoardName “GeForce GTX 970”
BusID “PCI:2:0:0”

Section “Screen”
Identifier “Screen0”
Device “Device0”
Monitor “Monitor0”
DefaultDepth 24
Option “Stereo” “0”
Option “nvidiaXineramaInfoOrder” “DFP-2”
Option “metamodes” “GPU-7b73f4b2-5211-0f20-32fb-4e29bfc82a31.DP-0: 3840x2160_60 +0+0 {ForceCompositionPipeline=On, ForceFullCompositionPipeline=On}, GPU-48e16c73-84d2-6b66-9625-b44b1ab1642d.DP-0: nvidia-auto-select +3840+0”
Option “MultiGPU” “Off”
Option “SLI” “off”
Option “BaseMosaic” “on”
SubSection “Display”
Depth 24

Please run as root and attach the resulting nvidia-bug-report.log.gz file to your post. You will have to rename the file ending to something else since the forum software doesn’t accept .gz files (nifty!).

nvidia-bug-report.log (3.2 MB)

Thanks generix.

Note: File is renamed but still is 'gz’compressed.

You’re using a basemosaic setup which doesn’t really work well on Geforce type cards and also isn’t very sensible in general when using only two monitors. You won’t have any more graphics performance, rather less because of the overhead copying data from one gpu to the other.
Better disable Basemosaic and connect both monitors to one gpu.