AOC G2460PG on Ubuntu 20.04 640x480 Radeon 5700 xt

Question

As the title says im using an AOC monitor and it will only let me use a 640x480 resolution.

I have a dell monitor on the 2nd DP and it works fine. The Dell Monitor registers as Dell 24" the AOC registers as Unknown Peripheral(Translated from danish).

Ive tryed doing CVT(OR what ever the command is) Using xrandr --newmode and --addmode to add a resolution i added both the max ress of the monitor as 60hz and 144 hz. But it doesnt let me use it.

The 640 resolution doesnt do fullscreen. It creates a small 640 window with alot of blackbars around it.

I tryed installing the AMD Pro drivers from the AMD website aswell same result. The monitor works great in windows.

On the AOC website i can find theese frequensies

1920 × 1080 at 144 Hz 158,110 144

Can i somehow add this to my xorg.conf and how do i do that if its possible ?

Answer 1

I found a solution.

Here are the modelines for your display:

  Detailed timing #1....... 1920x1080p at 85Hz (16:9)
    Modeline............... "1920x1080" 198,500 1920 1968 2000 2080 1080
    1083 1088 1124 +hsync -vsync
  Detailed timing #2....... 1920x1080p at 100Hz (16:9)
    Modeline............... "1920x1080" 235,500 1920 1968 2000 2080 1080 1083 1088 1133 +hsync -vsync
  Detailed timing #3....... 1920x1080p at 120Hz (16:9)
    Modeline............... "1920x1080" 285,500 1920 1968 2000 2080 1080 1083 1088 1144 +hsync -vsync
  Detailed timing #4....... 1920x1080p at 144Hz (16:9)
    Modeline............... "1920x1080" 325,080 1920 1944 1976 2056 1080 1083 1088 1098 +hsync +vsync

1. Check if they work with the following commands:

    xrandr --newmode "1920x1080_85.00" 198.500 1920 1968 2000 2080 1080 1083 1088 1124 +Hsync -Vsync
    xrandr --addmode DisplayPort-0 "1920x1080_85.00"
    xrandr --output DisplayPort-0 --mode "1920x1080_85.00"
   

2. If they work make a 20-monitor.conf at /usr/share/X11/xorg.conf:

   Section "Monitor"
       Identifier "Displayport-0"
       Modeline "1920x1080_85.00" 198.500 1920 1968 2000 2080 1080 1083 1088 1124 +hsync -vsync
       Option "PreferredMode" "1920x1080_85.00"
   EndSection
   
   Section "Screen"
       Identifier "Screen0"
       Monitor "Displayport-0"
       DefaultDepth 24
       SubSection "Display"
           Modes "1920x1080_85.00"
       EndSubSection
   EndSection
   
   Section "Device"
       Identifier "Device0"
       Driver "amdgpu"
   EndSection
   
   

That should fix your problem.

This page for monitor settings on the Arch wiki provides clarification