Multiple monitor refresh rate with xrandr misreporting

zegrammer · 2020-03-19 17:57:02

I'm having some trouble setting the refresh rate for one of my monitors while I have the other one connected.

If I only have the one monitor connected, it works great at 2560x1440@165hz. However as soon as I plugin in the second monitor (1920x1080@60) I cannot get the first monitors refresh rate to exceed 60z, even though it shows that its at 165hz.

➜  ~ lspci -k | grep -EA3 'VGA|3D|Display'
01:00.0 VGA compatible controller: NVIDIA Corporation GP102 [GeForce GTX 1080 Ti] (rev a1)
Subsystem: Gigabyte Technology Co., Ltd GP102 [GeForce GTX 1080 Ti]
Kernel driver in use: nvidia
Kernel modules: nouveau, nvidia_drm, nvidia

The command I was using with both monitors is

xrandr --output HDMI-2 --mode 1920x1080 --output DP-0 --mode 2560x1440 --rate 165.00 --right-of HDMI-2

➜  ~ xrandr
Screen 0: minimum 8 x 8, current 4480 x 1440, maximum 32767 x 32767
HDMI-0 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 598mm x 336mm
   1920x1080     60.00*+  59.94    50.00    60.05    60.00    50.04  
   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 connected primary 2560x1440+1920+0 (normal left inverted right x axis y axis) 598mm x 336mm
   2560x1440     59.95 + 165.00*  144.00   120.00    99.95    84.98    23.97  
   1024x768      60.00  
   800x600       60.32  
   640x480       59.94  
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)
DP-4 disconnected (normal left inverted right x axis y axis)
DP-5 disconnected (normal left inverted right x axis y axis)

Now it claims that it is 165hz but it is actually only 60. Any ideas on how to get around this?

seth · 2020-03-19 22:10:50

Can you get it to 99.95 Hz? 120 Hz?

zegrammer · 2020-03-20 00:06:42

It can be set to any of those refresh rates, but it tests at 60hz regardless of what you set it to. It also works fine in windows, so the GPU doesn't have any issues handling it.

Last edited by zegrammer (2020-03-20 00:07:16)

seth · 2020-03-20 11:43:57

The nvidia blob would have to report the wrong frequency to randr … does nvidia-settings also show the wrong frequency?
Random guess: do you use a (v'syncing) compositor?

zegrammer · 2020-03-20 19:12:57

Yes nvidia also reports the incorrect requency.

It says 165.00hz

-image removed

I'm using mutter I believe? Whatever came with gnome.

-image removed

Last edited by zegrammer (2020-03-20 23:31:44)

zegrammer · 2020-03-20 19:41:18

Looks like this is an issue with GDM

https://www.reddit.com/r/gnome/comments … ems_to_be/

seth · 2020-03-20 21:32:08

Please replace the oversized images w/ thumbnails or links (forum max is 200x200px)

late1635 wrote:

LightDM with gnome still had the problem.

Sound more like it's actually gnome/mutter (what would make more sense)
Also https://gitlab.gnome.org/GNOME/mutter/issues/503 and https://gitlab.gnome.org/GNOME/mutter/issues/148 and some more.
https://gitlab.gnome.org/GNOME/mutter/i … ote_463305 should be particularily interesting (and confirm my suspicion that mutter syncs to the "wrong" output and the High FPS monitor simply adapts)

zegrammer · 2020-03-20 23:32:48

Alright thanks for your help

Arch Linux

#1 2020-03-19 17:57:02

Multiple monitor refresh rate with xrandr misreporting

#2 2020-03-19 22:10:50

Re: Multiple monitor refresh rate with xrandr misreporting

#3 2020-03-20 00:06:42

Re: Multiple monitor refresh rate with xrandr misreporting

#4 2020-03-20 11:43:57

Re: Multiple monitor refresh rate with xrandr misreporting

#5 2020-03-20 19:12:57

Re: Multiple monitor refresh rate with xrandr misreporting

#6 2020-03-20 19:41:18

Re: Multiple monitor refresh rate with xrandr misreporting

#7 2020-03-20 21:32:08

Re: Multiple monitor refresh rate with xrandr misreporting

#8 2020-03-20 23:32:48

Re: Multiple monitor refresh rate with xrandr misreporting

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