Ubuntu 20.04.0 LTS Maximum Screen Resolution too low

Question

I have recently installed Ubuntu on a flash drive, and have a two monitor setup, one 21:9 screen and a 16:9 on top. The 21:9 screen is setup just fine however, in my settings menu, the maximum resolution I can select for my 16:9 monitor is 1600x900 despite the fact that it is a 1920x1080 monitor. In the terminal, I ran:

$ xrandr -q
Screen 0: minimum 8 x 8, current 2560 x 1980, maximum 16384 x 16384
DVI-I-0 disconnected (normal left inverted right x axis y axis)
DVI-I-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected primary 2560x1080+0+900 (normal left inverted right x axis y axis) 798mm x 334mm
   2560x1080     60.00*+
   1920x1080     60.00    59.94    50.00    29.97    60.05    60.00    50.04  
   1680x1050     59.95  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1280x720      60.00    59.94    50.00  
   1152x864      75.00  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       59.94  
   640x480       75.00    59.94    59.93  
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DVI-D-0 connected 1600x900+418+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768      60.00 +
   1600x900      59.82* 
   1400x900      59.88  
   1368x768      59.88    59.85  
   1360x768      59.96    59.80  
   1280x800      59.91    59.81  
   1280x720      59.86    59.74  
   1152x864      60.00  
   1024x576      59.90    59.82  
   960x540       59.82    59.63  
   864x486       59.92    59.57  
   800x600       72.19    60.32    56.25  
   800x450       59.82  
   700x450       59.88  
   684x384       59.88    59.85  
   680x384       59.96    59.80  
   640x480       59.94  
   640x400       59.98    59.88  
   640x360       59.86    59.83  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.82    59.63  
   432x243       59.92    59.57  
   400x300       72.19  
   320x240       60.05  

And it seems like it is not allowing me to be able to select 1920x1080. Is there a reason for this? For reference, I am using a GTX 970 GPU. Thank you.

Solution

Using the NVidia Server settings I could manage my screens on a GTX 760. The Xorg conf that the application created was copied to /etc/X11/xorg.conf.d/my.conf:

That of course makes only sense, if the application detects your monitors right. Otherwise you'd need to add the missing EDID information. This is a way to try out if the resolution works:

xrandr --output DVI-D-0 --mode 1920x1080 --rate 60

If that doesn't work and the Nvidia Server Settings does not recognize your monitor size you may have to add it to your "my.conf" file mentioned above:(change the resolutions -that is only an example!)

Section "Monitor"
    Identifier      "External DVI"
    Modeline        "1280x1024_60.00"  108.88  1280 1360 1496 1712  1024 1025 1028 1060  -HSync +Vsync
    Option          "PreferredMode" "1280x1024_60.00"
EndSection

Reboot. If a problem occurs just remove that conf file and restart - then no harm is done.

Comments

[Zernst]

Thank you for taking the time to answer. Unfortunately, it does look like I have to edit the config file. However, I am running into the problem where it opens as read-only and is telling me I don't have permission to save it. Is there a reason for this? Thanks.

[kanehekili]

yes. You have to use "sudo" to change anything out of your home directory. One of the intricate security measures of Linux , that makes it so save. Just to make sure: Is the nvidia app not recognizing your monitor size?

[Zernst]

Hello, I used the sudo command to make the changes, restarted, and it worked! The nvidia app did not recognize the monitor size, but I was able to change the resolution after changing the config file. Thank you!

[kanehekili]

Thanks for the feedback! Good to hear it works. This problem occurs when the monitor does not sent the correct/complete EDID data to the X server.