Multiple Monitors, Different Scalings Bug

[sonicaidan37]

I am on the newest 64-bit version of Linux Mint (20.2) and I'm encountering issues in Cinnamon with using multiple monitors with different scalings. Any help would be appreciated.

My laptop has a 3840x2160 (16:9) resolution. As a result, it needs the User interface scale setting set to Automatic (2x); Mint did this automatically and everything works great with just my laptop screen.
However, I want to use two extra monitors with it:
- 2560x1080 (21:9) through HDMI to mini-displayport (monitor-end is HDMI, laptop-end is mini-displayport; cord with two different ends), normal 1x UI scaling is optimal
- 1920x1080 (19:9) through HDMI to HDMI, normal 1x UI scaling is optimal

Here are what the Display preferences show:
https://imgur.com/a/s3tvGax (image 1)

There are two methods I tried to adjust the scalings: the Display preferences GUI and the xrandr command in the Terminal.

When I only plug in the 1920x1080 monitor and leave 2x UI scaling, my laptop still looks great but the 1920x1080 monitor is extremely large. Unfortunately, Cinnamon's Display preferences do not allow different UI scalings for different monitors. It also requires the UI scaling to be set to Normal (1x) in order to use Fractional Scaling to set custom scalings, which can be set per monitor. So, when I change the UI scaling to Normal (1x), as expected, the 1920x1080 monitor now looks great but everything on my 4k laptop screen looks extremely small. However, when I change Fractional Scaling on my laptop screen to: 200% (scaled resolution: 1920x1080), absolutely nothing happens; this is bug #1. So, I use the following command in the Terminal window:

Code: Select all

xrandr --output HDMI-0 --scale 2x2

This works and I can use my laptop with the 1920x1080 monitor just fine. I need to run this command every time I unplug/replug the monitor, but at least it works.

The biggest issue comes with the 2560x1080 monitor, with or without the 1080x1920 monitor involved.
When I plug in the three monitors and leave 2x UI scaling, my laptop still looks great but just as before, the external monitor pictures are large. The Display preferences issue is the same: laptop screen Fractional Scaling doesn't work when UI scaling is set to Normal (1x), UI scaling cannot be set per monitor. The 1920x1080 monitor is fixed with the same command: xrandr --output HDMI-0 --scale 2x2

However, the 2560x1080 monitor is not fixed with a similar command (xrandr --output DP-0.8 --scale 2x2). The result is it now overlaps with my laptop screen; this is bug #2. Take a look:
https://imgur.com/a/s3tvGax (image 2)

We can see what happened in the Display preferences window. While the 1920x1080 montor stayed put and behaved, the 2560x1080 monitor is now overlapped:
https://imgur.com/a/s3tvGax (image 3)
When I try to pull the "red monitor box" back into place and click Apply, it overrides the xrandr commands and resets both monitors back to 2x UI scaling.

When I set the UI Scaling to Normal (1x), both external monitors behave and work fine but my laptop screen doesn't. Adjusting it through Fractional Scaling or with the xrandr command does absolutely nothing and the screen is still extremely small. I tried xrandr --output eDP-1-1 --scale with all sorts of scaling values but it changes nothing.

Does anyone have any ideas?
Thanks!

[SMG]

Does anyone have any ideas?

Welcome to the forum, sonicaidan37.

None of your images are visible (they all require signing in to some account).

Please give us information about your install by entering this command in a terminal: inxi -Fxxxrz
Click </> from the mini toolbar above the textbox where you type your reply and then place your cursor between the code markers and paste the results of the command between the code markers [code]Results[/code]. This will let us know how Mint sees your hardware.

Please also provide the output of xrandr with both external monitors attached and enclose the results in code tags.

[sonicaidan37]

Does anyone have any ideas?

Welcome to the forum, sonicaidan37.

None of your images are visible (they all require signing in to some account).

Please give us information about your install by entering this command in a terminal: inxi -Fxxxrz
Click </> from the mini toolbar above the textbox where you type your reply and then place your cursor between the code markers and paste the results of the command between the code markers [code]Results[/code]. This will let us know how Mint sees your hardware.

Please also provide the output of xrandr with both external monitors attached and enclose the results in code tags.

Thanks for the reply! I also updated the image links in the post, hopefully that works now.
There was a recent update for Mint, but it still didn't fix anything.

Here's that code outputs:

Code: Select all

sonicaidan37@AlienPC:~$ inxi -Fxxxrz
System:
  Kernel: 5.4.0-94-generic x86_64 bits: 64 compiler: gcc v: 9.3.0 
  Desktop: Cinnamon 5.2.7 wm: muffin 5.2.0 dm: LightDM 1.30.0 
  Distro: Linux Mint 20.3 Una base: Ubuntu 20.04 focal 
Machine:
  Type: Laptop System: Alienware product: Alienware m15 v: 2.10.0 
  serial: <filter> Chassis: type: 10 serial: <filter> 
  Mobo: Alienware model: 0900DH v: A00 serial: <filter> UEFI: Alienware 
  v: 2.10.0 date: 09/29/2021 
Battery:
  ID-1: BAT0 charge: 86.3 Wh condition: 86.3/90.0 Wh (96%) volts: 13.0/11.4 
  model: DELL K69WH877 type: Li-ion serial: <filter> status: Full 
CPU:
  Topology: 6-Core model: Intel Core i7-8750H bits: 64 type: MT MCP 
  arch: Kaby Lake rev: A L2 cache: 9216 KiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx 
  bogomips: 52799 
  Speed: 1100 MHz min/max: 800/4100 MHz Core speeds (MHz): 1: 1100 2: 1100 
  3: 1100 4: 1100 5: 1100 6: 1100 7: 1100 8: 1100 9: 1100 10: 1100 11: 1100 
  12: 1100 
Graphics:
  Device-1: Intel UHD Graphics 630 vendor: Dell driver: i915 v: kernel 
  bus ID: 00:02.0 chip ID: 8086:3e9b 
  Device-2: NVIDIA TU106M [GeForce RTX 2060 Mobile] vendor: Dell 
  driver: nvidia v: 495.46 bus ID: 01:00.0 chip ID: 10de:1f11 
  Display: x11 server: X.Org 1.20.13 driver: modesetting,nvidia 
  unloaded: fbdev,nouveau,vesa 
  resolution: 1920x1080~75Hz, 2560x1080~60Hz, 3840x2160~60Hz 
  OpenGL: renderer: NVIDIA GeForce RTX 2060/PCIe/SSE2 v: 4.6.0 NVIDIA 495.46 
  direct render: Yes 
Audio:
  Device-1: Intel Cannon Lake PCH cAVS vendor: Dell driver: snd_hda_intel 
  v: kernel bus ID: 00:1f.3 chip ID: 8086:a348 
  Device-2: NVIDIA TU106 High Definition Audio vendor: Dell 
  driver: snd_hda_intel v: kernel bus ID: 01:00.1 chip ID: 10de:10f9 
  Sound Server: ALSA v: k5.4.0-94-generic 
Network:
  Device-1: Qualcomm Atheros Killer E2500 Gigabit Ethernet 
  vendor: Bigfoot Networks driver: alx v: kernel port: 3000 bus ID: 6f:00.0 
  chip ID: 1969:e0b1 
  IF: enp111s0 state: down mac: <filter> 
  Device-2: Intel Wireless-AC 9260 vendor: Bigfoot Networks driver: iwlwifi 
  v: kernel port: 3000 bus ID: 70:00.0 chip ID: 8086:2526 
  IF: wlp112s0 state: up mac: <filter> 
Drives:
  Local Storage: total: 476.94 GiB used: 111.72 GiB (23.4%) 
  ID-1: /dev/nvme0n1 vendor: Toshiba model: KXG50ZNV512G NVMe 512GB 
  size: 476.94 GiB speed: 31.6 Gb/s lanes: 4 serial: <filter> rev: AADA4106 
  scheme: GPT 
Partition:
  ID-1: / size: 467.96 GiB used: 111.71 GiB (23.9%) fs: ext4 
  dev: /dev/nvme0n1p2 
Sensors:
  System Temperatures: cpu: 63.0 C mobo: 27.8 C gpu: nvidia temp: 57 C 
  Fan Speeds (RPM): N/A 
Repos:
  No active apt repos in: /etc/apt/sources.list 
  Active apt repos in: /etc/apt/sources.list.d/additional-repositories.list 
  1: deb https://cloud.r-project.org/bin/linux/ubuntu focal-cran40/
  Active apt repos in: /etc/apt/sources.list.d/google-chrome.list 
  1: deb [arch=amd64] https://dl.google.com/linux/chrome/deb/ stable main
  Active apt repos in: /etc/apt/sources.list.d/graphics-drivers-ppa-focal.list 
  1: deb http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu focal main
  Active apt repos in: /etc/apt/sources.list.d/insync.list 
  1: deb http://apt.insync.io/mint uma non-free contrib
  Active apt repos in: /etc/apt/sources.list.d/linuxuprising-java-focal.list 
  1: deb http://ppa.launchpad.net/linuxuprising/java/ubuntu focal main
  Active apt repos in: /etc/apt/sources.list.d/lutris-team-lutris-focal.list 
  1: deb http://ppa.launchpad.net/lutris-team/lutris/ubuntu focal main
  Active apt repos in: /etc/apt/sources.list.d/official-package-repositories.list 
  1: deb http://packages.linuxmint.com una main upstream import backport #id:linuxmint_main
  2: deb http://archive.ubuntu.com/ubuntu focal main restricted universe multiverse
  3: deb http://archive.ubuntu.com/ubuntu focal-updates main restricted universe multiverse
  4: deb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse
  5: deb http://security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse
  6: deb http://archive.canonical.com/ubuntu/ focal partner
  Active apt repos in: /etc/apt/sources.list.d/spotify.list 
  1: deb http://repository.spotify.com stable non-free
  Active apt repos in: /etc/apt/sources.list.d/vscode.list 
  1: deb [arch=amd64,arm64,armhf] http://packages.microsoft.com/repos/code stable main
  Active apt repos in: /etc/apt/sources.list.d/zulu-openjdk.list 
  1: deb [ arch=amd64,arm64 ] https://repos.azul.com/zulu/deb/ stable main
Info:
  Processes: 317 Uptime: 12m Memory: 15.43 GiB used: 1.85 GiB (12.0%) 
  Init: systemd v: 245 runlevel: 5 Compilers: gcc: 9.3.0 alt: 9 Shell: bash 
  v: 5.0.17 running in: gnome-terminal inxi: 3.0.38 

For xrandr:

Code: Select all

sonicaidan37@AlienPC:~$ xrandr --listmonitors
Monitors: 3
 0: +*eDP-1-1 3840/344x2160/193+2560+0  eDP-1-1
 1: +DP-0.8 2560/673x1080/284+0+0  DP-0.8
 2: +HDMI-0 1920/476x1080/268+6400+0  HDMI-0

[SMG]

Thanks for the reply! I also updated the image links in the post, hopefully that works now.

They are visible now. Thanks.

A possibility to keep in mind is upgrading to a newer kernel series. I generally recommend that for 8th-gen Intel and newer. That would provide an updated Intel i915 driver (which might be a factor in this situation) and may help give better temperature control. CPU temp seems a bit high for the listed speeds.
Sensors:
System Temperatures: cpu: 63.0 C mobo: 27.8 C gpu: nvidia temp: 57 C
Fan Speeds (RPM): N/A

For xrandr:

Code: Select all

sonicaidan37@AlienPC:~$ xrandr --listmonitors
Monitors: 3
 0: +*eDP-1-1 3840/344x2160/193+2560+0  eDP-1-1
 1: +DP-0.8 2560/673x1080/284+0+0  DP-0.8
 2: +HDMI-0 1920/476x1080/268+6400+0  HDMI-0

May I please see the output of xrandr with all three monitors attached? You supplied the output of xrandr --listmonitors.

[sonicaidan37]

Thanks for the reply! I also updated the image links in the post, hopefully that works now.

They are visible now. Thanks.

A possibility to keep in mind is upgrading to a newer kernel series. I generally recommend that for 8th-gen Intel and newer. That would provide an updated Intel i915 driver (which might be a factor in this situation) and may help give better temperature control. CPU temp seems a bit high for the listed speeds.
Sensors:
System Temperatures: cpu: 63.0 C mobo: 27.8 C gpu: nvidia temp: 57 C
Fan Speeds (RPM): N/A

For xrandr:

Code: Select all

sonicaidan37@AlienPC:~$ xrandr --listmonitors
Monitors: 3
 0: +*eDP-1-1 3840/344x2160/193+2560+0  eDP-1-1
 1: +DP-0.8 2560/673x1080/284+0+0  DP-0.8
 2: +HDMI-0 1920/476x1080/268+6400+0  HDMI-0

May I please see the output of xrandr with all three monitors attached? You supplied the output of xrandr --listmonitors.

Thanks for that tip! I just barely upgraded my kernel series. Here's the xrandr output:

Code: Select all

sonicaidan37@AlienPC:~$ xrandr
Screen 0: minimum 8 x 8, current 8320 x 2160, maximum 32767 x 32767
HDMI-0 connected 1920x1080+6400+0 (normal left inverted right x axis y axis) 476mm x 268mm
   1920x1080     74.97*+  60.00    59.94    50.00  
   1680x1050     59.95  
   1440x900      59.89  
   1280x1024     60.02  
   1280x800      59.81  
   1280x720      60.00    59.94    50.00  
   1152x864      75.00  
   1024x768      70.07    60.00  
   800x600       60.32    56.25  
   720x576       50.00  
   720x480       59.94  
   640x480       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)
DP-0.8 connected 2560x1080+0+0 (normal left inverted right x axis y axis) 673mm x 284mm
   2560x1080     60.00*+
   1920x1080     60.00    60.00    59.94    50.00    23.98  
   1680x1050     59.95  
   1280x1024     75.02    60.02  
   1280x800      59.81  
   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  
eDP-1-1 connected primary 3840x2160+2560+0 (normal left inverted right x axis y axis) 344mm x 193mm
   3840x2160     60.00*+  59.98    48.03    59.97  
   3200x1800     59.96    59.94  
   2880x1620     59.96    59.97  
   2560x1600     59.99    59.97  
   2560x1440     59.99    59.99    59.96    59.95  
   2048x1536     60.00  
   1920x1440     60.00  
   1856x1392     60.01  
   1792x1344     60.01  
   2048x1152     59.99    59.98    59.90    59.91  
   1920x1200     59.88    59.95  
   1920x1080     60.01    59.97    59.96    59.93  
   1600x1200     60.00  
   1680x1050     59.95    59.88  
   1600x1024     60.17  
   1400x1050     59.98  
   1600x900      59.99    59.94    59.95    59.82  
   1280x1024     60.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.99    59.97    59.81    59.91  
   1152x864      60.00  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98  
   576x432       60.06  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
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)
  1680x1050 (0x205) 146.250MHz -HSync +VSync
        h: width  1680 start 1784 end 1960 total 2240 skew    0 clock  65.29KHz
        v: height 1050 start 1053 end 1059 total 1089           clock  59.95Hz
  1280x1024 (0x20d) 108.000MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock  63.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  60.02Hz
  1440x900 (0x20e) 106.500MHz -HSync +VSync
        h: width  1440 start 1520 end 1672 total 1904 skew    0 clock  55.93KHz
        v: height  900 start  903 end  909 total  934           clock  59.89Hz
  1280x800 (0x21a) 83.500MHz -HSync +VSync
        h: width  1280 start 1352 end 1480 total 1680 skew    0 clock  49.70KHz
        v: height  800 start  803 end  809 total  831           clock  59.81Hz
  1024x768 (0x222) 65.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock  48.36KHz
        v: height  768 start  771 end  777 total  806           clock  60.00Hz
  800x600 (0x231) 40.000MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock  37.88KHz
        v: height  600 start  601 end  605 total  628           clock  60.32Hz
  800x600 (0x232) 36.000MHz +HSync +VSync
        h: width   800 start  824 end  896 total 1024 skew    0 clock  35.16KHz
        v: height  600 start  601 end  603 total  625           clock  56.25Hz
  640x480 (0x240) 25.175MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.47KHz
        v: height  480 start  490 end  492 total  525           clock  59.94Hz

[SMG]

The biggest issue comes with the 2560x1080 monitor, with or without the 1080x1920 monitor involved.

This is the first time I've ever seen a connection listed as a fraction of a number. This is the DP-0.8 connection which is the miniDP (laptop) to HDMI (monitor) connection. Normally, the connections look like the other ones listed. They are either -0, -1, -1-1, or something similar with whole numbers.

It is possible something in the conversion from DP to HDMI is what causes the odd results you are seeing when you try to scale that monitor. I did find this Mini display port to Hdmi 4k 60Hz. where several people discussed how they had different results when using different cables or connecting to different monitors with the same cable.

So it is possible there is a hardware factor at play in the results you are seeing.

UI scaling cannot be set per monitor.

I do not know if this will help because it seems you change which monitors you are using, but here is a suggestion I found as a Feature Request for Cinnamon Feature request: Display / custom per screen Fractional Scaling #9523 . To get the desired output, the person manually modified their cinnnamon-monitors.xml file. That file is in the .config directory (hidden directory) under /home. It is created when you click Apply in the Display app.

When I set the UI Scaling to Normal (1x), both external monitors behave and work fine but my laptop screen doesn't. Adjusting it through Fractional Scaling or with the xrandr command does absolutely nothing and the screen is still extremely small. I tried xrandr --output eDP-1-1 --scale with all sorts of scaling values but it changes nothing.

This is where I think a custom cinnamon-monitors.xml file might be worth trying. You could create the initial file with this setup and then go in and change the scaling for the laptop screen.

[sonicaidan37]

...

There must have been a recent update! Or maybe it was updating the kernel. It looks like the User Interface Scale set to Double (Hi-DPI) now allows for fractional scaling as well. Leaving the UI scale as double for my laptop screen and 100% fractional for both my other monitors now works fine. I'll have to adjust that .xml file you mentioned though so that I don't have to keep messing with the settings every single time I unplug and replug my monitors back in.
Thanks so much for all of your help!

[SMG]

There must have been a recent update!

I did get some updates on the 11th, but because the mirrors get updates at different times I do not know when you might have gotten them in relation to when I did. I do not recall any which might have impacted this scenario, but maybe they did.

Or maybe it was updating the kernel.

Are you using the 5.11 or 5.13 kernel?

I'll have to adjust that .xml file you mentioned though so that I don't have to keep messing with the settings every single time I unplug and replug my monitors back in.

I am not sure how that will work if you do not have the monitors plugged in all the time. That will be something you have to test.

[sonicaidan37]

There must have been a recent update!

I did get some updates on the 11th, but because the mirrors get updates at different times I do not know when you might have gotten them in relation to when I did. I do not recall any which might have impacted this scenario, but maybe they did.

Or maybe it was updating the kernel.

Are you using the 5.11 or 5.13 kernel?

I'll have to adjust that .xml file you mentioned though so that I don't have to keep messing with the settings every single time I unplug and replug my monitors back in.

I am not sure how that will work if you do not have the monitors plugged in all the time. That will be something you have to test.

I am using the 5.13 kernel now, thanks to you. It still seems to be working now with using the Double (Hi-DPI) UI scaling setting, then setting the lower resolution monitors' fractional scalings back to 100%. I'm surprised and grateful for how well it's been working now. I thought for a moment I'd have to move away from Cinnamon and try a different desktop environment.