Triple screen setup on X11

[Firestone]

Hi everyone.

For the last 8 months I've been using ETS 2 exclusively on Linux, and despite what a lot of people report, I actually got some performance improvements compared to running it on Windows 10, which I've done pretty much since the release, except for
some years on macOS (before the arm-switch).

My hardware setup is and AMD 7700X combined with a nVidia RTX 2080ti.
On the open beta of 1.59, I actually made the switch from OpenGL to Vulkan renderer in my config file, and it seems to run very well and stable on my setup, outperforming the Windows-version in my case for some reason.

Now to the topic: One of the really few reasons I still boot into Windows to do ETS2-stuff, is that I still got my workflow there for my skinpacks (Photoshop, ModsStudio2 and so on...), but planning to move that also to Linux as this is my
daily gaming system combined with macOS which is my primary setup when not gaming.
Recently I bought three similar 2k displays and connected to use as a triple screen setup for ETS2. This works fine through nVidia surround in Windows, but I'm curious now if someone else has done some experiments with a triple screen setup
in Linux? I have read a lot of posts about it, and it seems like something happened after v1.50.

I have never had success making multimon setup work on Linux, and last night I started some new experiments on it with no success.
I tried to use xrandr to merge the displays, and make the game see this as one wide screen, but it does not become available as a resolution inside ETS2. Only the resolution of one of the screens.
Tried to manipulate the resolution in the config file, and somehow managed to get something working when setting r_fullscreen = 0 , which I beilieve will make the game run in a bordered window by default.
This is the only setup I've experienced this to work a little bit, at least triggering the left and right monitor to show something in game.
However, it will only show a strange stretched view of everything, just like the aspect ratio is way off.

I haven't tried the gamescope-path so far, but I'm curious if someone else here did?
There is not a deb-package available directly for Linux mint 22.3 as far as I can see, and I haven't had the patience yet to mess around with it, fighting compilers or whatever it takes to get it installed properly.

[skyking_eam]

I'm using triple screen under Linux since a few years on 3 WQHD Monitors with a Ryzen 9800X3D and an AMD RX6900XT GPU. So maybe i can give you some advise on that.

First of all, i would recommend to run the game with Proton compatibility layer. Even the native OpenGL version has evolved in the past performance wise, i have noticeable better performance with DX11 - especially when running in triple screen. Vulkan implementation is still in a early stage without optimizations. And on top of that, triple screen is not working with the current Vulkan implementation (at least with my AMD GPU).

Running triplescreen on Linux is basically the same procedure as on Windows which i described in this post: viewtopic.php?p=2073189#p2073189
So xrandr/Xinerama/gamescoppe/Nvidia Surround/AMD Eyefinity or other multi-monitor configurations are not strictly necessary.

From your previous post, I gather that you use Linux Mint and probably Cinnamon desktop environment. There are some problems with this method when using the native Linux version which you don't have with Proton: The game window doesn't cover the taskbar, so you have to manually auto-hide taskbar on all 3 screens. The other problem is, that you can't use the mouse pointer when tabbing out to the desktop.

But if you really want to use the Linux version, there is a workaround for that which i can explain if you want.

[Firestone]

Thanks a lot for your reply skyking_eam !

Yes, you're correct, I'm on the Cinnamon desktop.

I did some more experiments, and you're right, the combination of Proton and dx11 is where I can squeeze the best performance actually. Tried OpenGL, DX12, DX11 and VK.
VK actually performs okay, but it will only give me two screens and some other glitches, which of course is expected at this stage.

And yes, using these settings:

Code: Select all

uset r_fullscreen "0"
uset r_windowed_borderless "1"
uset r_mode_height "1440"
uset r_mode_width "7680"

And afterwards in the developer console:

Code: Select all

g_mode 7680 1440 60 0

Now it covers all three screens, excellent!

I used Proton Experimental as the compatibility-layer, I don't know if there are any performance-differences between these versions, but I guess I'll find out.

Just because I'm curious and nerd, would you mind explaining what could be done to the native version to achieve about the same? I got the impression that there were methods to do so.

[skyking_eam]

I made a script and bind it to a custom shortcut in Cinnamon Keyboard settings to toggle taskbar for all 3 screens simultaneously and another to disable window title-bar:

toggle_taskbar.sh:

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#!/bin/bash
state=$(gsettings get org.cinnamon panels-autohide)
if [ "$state" == "['1:true', '3:true', '2:true']" ]; then
    gsettings set org.cinnamon panels-autohide "['1:false', '3:false', '2:false']"
else
    gsettings set org.cinnamon panels-autohide "['1:true', '3:true', '2:true']"
fi

For disabling window title-bar you can directly add this command when creating the shortcut (xprop is part of x11-utils package in Ubuntu) :

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xprop -name 'Euro Truck Simulator 2' -f _MOTIF_WM_HINTS 32c -set _MOTIF_WM_HINTS "0x2, 0x0, 0x2, 0x0, 0x0"

After starting the native Linux game in triplescreen you just have to press the key shortcuts to have the game window fully expanded to your workspace.

[Firestone]

Thanks a lot! Really appreciate it!

[Firestone]

Just a followup on this topic...

This line:

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g_mode 7680 1440 60 0

The third parameter (60) is the refresh rate.

Have you ever encountered that this parameter does anything else than 60Hz?
When the game is launched, and the ets game is showing in this panorama widescreen mode before entering this line to stretch it correctly across the screens, my monitors inputs show a 180Hz signal.
But after using that command, all displays changes 60Hz, even if the third parameter is 180, 120 or whatever the monitors support.

Is this a limitation somewhere in ETS itself or maybe a proton-issue?

[skyking_eam]

I didn't take much attention to the refresh rate since my center monitor only supports 60, 100, 120, and 144 Hz, while my two side monitors are limited to 60 and 75 Hz. So i have set all monitors to 60 Hz. And if i set different refresh rates, the gameplay feels stuttery.

[Firestone]

Allright. In my setup, there are three equal 180Hz displays running on DisplayPort. Desktop is 180Hz, but the game forces 60Hz...
I guess I'll have to do some experiments with xrandr and try to fool it into another refreshrate. I guess it might got something to do with X11 does not find any resolutions like 5760x1080 with specific refreshrates.....