I’m setting up a workstation with 2 GPU (Nvidia GTX1050 Ti) and 6 displays (samsung md230x6) on Ubuntu 18.04.
It’s all working fine except that the desktop shows only on the displays of the first GPU; the other three are black: I cannot move any window upon but the mouse cursor actually shows as a black cross with white outline.
Funny fact is that I can actually change the color of the black screens via nvidia-settigs GUI Color Correction.
The same rig works fine on Win10.
I tried to physically disconnect three monitors and modified xorg.conf following https://wiki.archlinux.org/index.php/multihead without any change.
$ xrandr
Screen 0: minimum 8 x 8, current 5760 x 1080, maximum 32767 x 32767
DVI-D-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 510mm x 287mm
1920x1080 60.00*+ 50.00
...
HDMI-0 disconnected (normal left inverted right x axis y axis)
DP-0 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 510mm x 278mm
1920x1080 60.00*+ 59.94 50.00
...
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 connected 1920x1080+3840+0 (normal left inverted right x axis y axis) 510mm x 287mm
1920x1080 60.00*+ 50.00
...
$ nvidia-smi
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 396.54 Driver Version: 396.54 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 GeForce GTX 105... Off | 00000000:01:00.0 On | N/A |
| 0% 46C P8 N/A / 120W | 624MiB / 4037MiB | 1% Default |
+-------------------------------+----------------------+----------------------+
| 1 GeForce GTX 105... Off | 00000000:02:00.0 On | N/A |
| 45% 29C P0 N/A / 75W | 64MiB / 4040MiB | 0% Default |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes: GPU Memory |
| GPU PID Type Process name Usage |
|=============================================================================|
| 0 953 G /usr/lib/xorg/Xorg 34MiB |
| 0 1003 G /usr/bin/gnome-shell 48MiB |
| 0 1250 G /usr/lib/xorg/Xorg 286MiB |
| 0 1393 G /usr/bin/gnome-shell 147MiB |
| 0 2355 G ...-token=C398224CE3FA660C9FF3A88B97994567 105MiB |
| 1 953 G /usr/lib/xorg/Xorg 30MiB |
| 1 1250 G /usr/lib/xorg/Xorg 31MiB |
+-----------------------------------------------------------------------------+
$ uname -a
Linux myhostname 4.15.0-33-generic #36-Ubuntu SMP Wed Aug 15 16:00:05 UTC 2018 x86_64 x86_64 x86_64 GNU/
$ lspci | grep VGA
01:00.0 VGA compatible controller: NVIDIA Corporation GP107 [GeForce GTX 1050 Ti] (rev a1)
02:00.0 VGA compatible controller: NVIDIA Corporation GP107 [GeForce GTX 1050 Ti] (rev a1)
/usr/share/X11/xorg.conf.d/10-nvidia.conf:
Section "OutputClass"
Identifier "nvidia"
MatchDriver "nvidia-drm"
Driver "nvidia"
Option "AllowEmptyInitialConfiguration"
ModulePath "/usr/lib/x86_64-linux-gnu/nvidia/xorg"
EndSection
/etc/X11/xorg.conf: https://gist.github.com/pliski/73a68ba3cd2b489a008e4c822db0c717
/var/log/Xorg.log: https://gist.github.com/pliski/b3ede6b301c16199e8ebd84f876fb8f2
See also:
_ https://askubuntu.com/questions/843561/3rd-monitor-showing-x-cursor
_ https://askubuntu.com/questions/1071480/ubuntu-18-04-display-disconnected
nvidia-bug-report.log.gz (143 KB)