Ubuntu 18.04 + Cuda 390 does NOT detect second monitor on displayport

My machine has NVIDIA Quadro K2200 graphic card with GPU.

I installed Ubuntu 18.04 and nvidia-390.48 as well as CUDA 9.0 (I use Cuda 9.0 because higher versions are not working with keras and tensor-flow).

Anyhow, cuda, keras, and tensorflow all work fine. However, Ubuntu is not detecting the second monitor which is connected through DisplayPort while the first one is connected through DVI port.

Here is the output of nvidia-smi:

+-----------------------------------------------------------------------------+
| NVIDIA-SMI 390.48                 Driver Version: 390.48                    |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|===============================+======================+======================|
|   0  Quadro K2200        Off  | 00000000:03:00.0  On |                  N/A |
| 42%   33C    P8     1W /  39W |    185MiB /  4035MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+

+-----------------------------------------------------------------------------+
| Processes:                                                       GPU Memory |
|  GPU       PID   Type   Process name                             Usage      |
|=============================================================================|
|    0       924      G   /usr/lib/xorg/Xorg                            99MiB |
|    0      1390      G   /usr/bin/gnome-shell                          73MiB |
|    0      1918      G   /usr/lib/firefox/firefox                       1MiB |
|    0      1991      G   /usr/lib/firefox/firefox                       1MiB |
|    0      2148      G   /usr/lib/firefox/firefox                       1MiB |
+-----------------------------------------------------------------------------+

and here is the output of xrandr:

Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384
DVI-I-0 disconnected (normal left inverted right x axis y axis)
DVI-I-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 531mm x 298mm
   1920x1080     60.00*+
   1280x1024     75.02    60.02  
   1152x864      75.00  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   640x480       75.00    59.94  
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)

and here is the content of my xorg.conf file:

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 390.48  (buildmeister@swio-display-x86-rhel47-07)  Thu Mar 22 01:07:32 PDT 2018

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
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"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       28.0 - 33.0
    VertRefresh     43.0 - 72.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
EndSection

Section "Files"
    ModulePath      "/usr/local/cuda/lib64/"
    ModulePath      "/usr/lib/xorg/modules"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Just to make sure, the DP monitor is connected to the DP on the nvidia graphics card, not the mainboard?
Did you check the cable, are you using any kind of converter or is it connected to a native DP monitor?

Here is a picture:

It is a monitor with DVI cable which is connected to DVI to DP converter and than plugged into the graphic card (I believe. I don’t see how I can connect it to the main board). The first monitor is connected directly through the DVI cable.

Thank You,
Nikola

Thanks. I borrowed an adapter from another computer and it worked with it. It turns out the adapter I had was broken. I cna’t believe I spent hours trying to figure out what was wrong with my installation when it was the hardware that failed. SMH.