tl;dr: I have an Ubuntu 19.10 setup that recognises both monitors (lspci
shows both and I get a cursor on the second one) but xrandr -q
and GNOME only see one of them. What might be the problem?
I set up a new system with a pair of GeForce RTX 2080 Ti cards and a 4K monitor connected to each via USB-C.
After installing Ubuntu 19.10, only one monitor came up. Running sudo nvidia-settings
gave me a sample xconfig, which I appended to /usr/share/X11/xorg.conf.d/10-nvidia.conf
. The result:
Section "OutputClass"
Identifier "nvidia"
MatchDriver "nvidia-drm"
Driver "nvidia"
Option "AllowEmptyInitialConfiguration"
ModulePath "/usr/lib/x86_64-linux-gnu/nvidia/xorg"
EndSection
# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 435.21
Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0" 0 0
Screen 1 "Screen1" RightOf "Screen0"
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
Option "Xinerama" "0"
EndSection
Section "Files"
EndSection
Section "InputDevice"
# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection
Section "InputDevice"
# generated from default
Identifier "Keyboard0"
Driver "kbd"
EndSection
Section "Monitor"
# HorizSync source: edid, VertRefresh source: edid
Identifier "Monitor0"
VendorName "Unknown"
ModelName "LG Electronics LG HDR 4K"
HorizSync 30.0 - 135.0
VertRefresh 56.0 - 61.0
Option "DPMS"
EndSection
Section "Monitor"
# HorizSync source: unknown, VertRefresh source: unknown
Identifier "Monitor1"
VendorName "Unknown"
ModelName "LG Electronics LG HDR 4K"
HorizSync 0.0 - 0.0
VertRefresh 0.0
Option "DPMS"
EndSection
Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce RTX 2080 Ti"
BusID "PCI:10:0:0"
EndSection
Section "Device"
Identifier "Device1"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce RTX 2080 Ti"
BusID "PCI:4:0:0"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "DFP-6"
Option "metamodes" "nvidia-auto-select +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "Screen1"
Device "Device1"
Monitor "Monitor1"
DefaultDepth 24
Option "Stereo" "0"
Option "metamodes" "nvidia-auto-select +0+0 {AllowGSYNC=Off}"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection
After rebooting, I still get GNOME on the one monitor. The other monitor, however, is a black screen with just the default X cursor (the glow on the right is just reflections on the monitor):
I also noticed two gdm3 sessions in htop, one running:
/usr/lib/xorg/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -background none -noreset -keeptty -verbose 3
The other running the same command line but with vt1 instead of vt2. Killing the vt2 one killed my GNOME session. Killing the other one, however, seemed to do nothing. I can even still see a cursor on the second monitor.
Afaict from Settings | Devices | Screen Display
, only one monitor is present:
Some additional data:
$ lspci | grep -i nvidia
04:00.0 VGA compatible controller: NVIDIA Corporation TU102 [GeForce RTX 2080 Ti Rev. A] (rev a1)
04:00.1 Audio device: NVIDIA Corporation TU102 High Definition Audio Controller (rev a1)
04:00.2 USB controller: NVIDIA Corporation TU102 USB 3.1 Controller (rev a1)
04:00.3 Serial bus controller [0c80]: NVIDIA Corporation TU102 UCSI Controller (rev a1)
0a:00.0 VGA compatible controller: NVIDIA Corporation TU102 [GeForce RTX 2080 Ti Rev. A] (rev a1)
0a:00.1 Audio device: NVIDIA Corporation TU102 High Definition Audio Controller (rev a1)
0a:00.2 USB controller: NVIDIA Corporation TU102 USB 3.1 Controller (rev a1)
0a:00.3 Serial bus controller [0c80]: NVIDIA Corporation TU102 UCSI Controller (rev a1)
$ xrandr -q
Screen 0: minimum 8 x 8, current 3840 x 2160, maximum 32767 x 32767
HDMI-0 disconnected (normal left inverted right x axis y axis)
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
USB-C-0 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 600mm x 340mm
3840x2160 60.00*+ 30.00
2560x1440 59.95
1920x1080 60.00 59.94
1600x900 60.00
1280x1024 60.02
1280x800 59.81
1280x720 60.00 59.94
1152x864 59.96
1024x768 60.00
800x600 60.32
720x480 59.94
640x480 59.94 59.93
$ nvidia-smi
Sun Dec 8 14:19:03 2019
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 435.21 Driver Version: 435.21 CUDA Version: 10.1 |
|-------------------------------+----------------------+----------------------+
| 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 RTX 208... Off | 00000000:04:00.0 On | N/A |
| 25% 32C P8 6W / 260W | 39MiB / 11019MiB | 0% Default |
+-------------------------------+----------------------+----------------------+
| 1 GeForce RTX 208... Off | 00000000:0A:00.0 On | N/A |
| 32% 41C P8 4W / 260W | 571MiB / 11016MiB | 4% Default |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes: GPU Memory |
| GPU PID Type Process name Usage |
|=============================================================================|
| 0 7142 G /usr/lib/xorg/Xorg 37MiB |
| 1 7142 G /usr/lib/xorg/Xorg 268MiB |
| 1 7351 G /usr/bin/gnome-shell 260MiB |
| 1 9360 G gnome-control-center 6MiB |
| 1 10505 G ...no-sandbox --gpu-preferences=IAAAAAAAAA 34MiB |
+-----------------------------------------------------------------------------+
Question: Why is only one of my monitors being picked up by GNOME and what can I do to fix this?
UPDATE: I've uploaded my /var/log/Xorg.0.log
. No smoking gun there, afaict.
/var/log/Xorg.0.log
for error messages.Xorg.0.log
it looks like bothGPU-0
andGPU-1
both try to useDP-6
but onlyGPU-0
gets to use it.