Change refresh rate on multimonitor

Question

I was trying to use xrandr to set the refresh rate on a cheapo Korean IPS monitor that I'm running on displayport. It's supposed to be 60hz, or else the screen does a frequent tear / reset colour test. If you see below DP-1-1-2 is showing 59.95*+ but it should be 60.

I've tried using:

xrandr --output DP-1-1-2 --rate 60.00

But it appears to have no effect. Similarly frustrating, the settings for the monitors do not show up in nvidia-settings (nor with sudo).

Help?

Screen 0: minimum 8 x 8, current 4480 x 2520, maximum 32767 x 32767
eDP-1-1 connected 1920x1080+2560+1080 (normal left inverted right x axis y axis) 346mm x 194mm
   1920x1080     59.93*+
   # ... snipped
DP-1-1 disconnected (normal left inverted right x axis y axis)
HDMI-1-1 disconnected (normal left inverted right x axis y axis)
DP-1-2 disconnected (normal left inverted right x axis y axis)
HDMI-1-2 disconnected (normal left inverted right x axis y axis)
DP-1-1-1 disconnected (normal left inverted right x axis y axis)
DP-1-1-2 connected 2560x1440+0+1080 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440     59.95*+
DP-1-2-1 connected primary 2560x1080+0+0 (normal left inverted right x axis y axis) 673mm x 284mm
   2560x1080     60.00*+
   1920x1080     60.00    60.00    50.00    59.94  
   1680x1050     59.88  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1152x864      75.00  
   1280x720      60.00    60.00    50.00    59.94  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       60.00    60.00    59.94    59.94  
   640x480       75.00    60.00    59.94    59.94  
   720x400       70.08  
DP-1-1-3 disconnected (normal left inverted right x axis y axis)
DP-1-2-2 disconnected (normal left inverted right x axis y axis)
DP-1-2-3 disconnected (normal left inverted right x axis y axis)

Possibly related: https://askubuntu.com/a/59626/231142 Looks as though you need to add the resolution as I am not seeing it on the list of supported resolutions for that monitor through xrandr. — Terrance, Jun 07 '19 at 21:35
I also tried using a complete line, it did not work either: xrandr --output DP-1-1-2 --mode 2560x1440 --rate 120.0 --primary — Brandon Bertelsen, Jun 07 '19 at 21:44
@Terrance I'm not sure what you mean. Could you provide an example? — Brandon Bertelsen, Jun 07 '19 at 21:52

score 1 · Answer 1 · answered Jul 03 '19 at 12:09

Here is a guide that describes the way xrandr operates.

It mentions that:

Displayed are the different connectors (i.e. VGA-0, DVI-0, S-Video, LVDS) along with the automatically detected resolutions using the EDID information obtained from the display.

In other words, the lines:

DP-1-1-2 connected 2560x1440+0+1080 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440     59.95*+

Are the direct EDID information provided by the display. So this display only supports a single mode:

resolution of 2560x1440
refresh rate of 59.95Hz.

Xrandr won't be able to set a different mode.

However it is not unheard of that a display EDID info are badly configured and that in reality the display supports additional modes. In that case, a potential workaround would be to use an EDID emulator to spoof the EDID capabilities of the screen, thus enabling additional modes in xrandr.

I ended up just buying a new monitor. It was less expensive than continuing to spend time on trying to fix it. — Brandon Bertelsen, Jul 05 '19 at 04:58

Change refresh rate on multimonitor

1 Answers1