Triples kde/X11 + free(v)sync and TearFree : 6900XT 7680x1440120fps

LMU Linux Triples

My setup runs 7680x1440 at 120hz/fps on a Radeon 6900XT
I did try KDE/Plasma 6 with wayland and gamescope (a lot) but there is always something going on, like
super smooth on normal testing, then on online situations with random frametime 'ticks' which I could not solve, likely related
to wayland VRR always on. Also, smooth frames for 2 laps then staring to lose sync.

In the end the most simple window manager, one that does not interfere or try to add smart rules is working best,
it is IceWM on X11, so I toook the time to configure icewm and it was worth it. But its a good chunk of work.

--> Before startimg LMU add the custom resolution to:
~/.local/share/Steam/steamapps/common/Le Mans Ultimate/UserData/Config_DX11.ini (my full config is bellow)
CustomVidRes=(7680, 1440) # Set your triples resolution.
WindowedMode=1 #set this
Borderless=0 #set this

-> Dont change anything else, save, close.

Framerate I set fix rate directly in LMU:
(generate proper frametime with cvt command, eg. (cvt 7680 1400 120))

slemke@gamingpc:~> grep "Max Framerate" ~/.local/share/Steam/steamapps/common/Le\ Mans\ Ultimate/UserData/player/Settings.JSON 
    "Max Framerate": 119.92,
  
### X11(xorg) Settings for my AMD: ###

For my radeon, I created this file:
/etc/X11/xorg.conf.d/10-radeon.conf with bellow content:
Section "Device"
Identifier "AMDgpu"  # or "Radeon"
Driver "amdgpu"     # or "radeon"
Option "TearFree" "on"
EndSection

This enables TearFree, needed!

### End X11(xorg) Settings: ###

gamemoderun (optional) - it is good to block screen saver.
Also install lact to underwolt the 6900XT - ofset -81 is optimal in my card.

setting up icewm takes time, if you get it close to your likings dont forget to save to reuse in future.

Do you also experience the issue with low fps / stuttering when the LMU UI overlay is on full? i get around 40-60fps drop with full overlay regardless of CEF settings.
I dont get the issue when overlay is set to minimal or off

As for max framerate, if i set it to match VideoRefreshRate mangohud avg reports 5 to 20fps lower.
Probably better off using VSyncMode=2

kde/wayland

MangoHUD I really only use to monitor, in my case I just fix the rate direct on the config with no vsync on, its quite smooth.
I do not really have a problem with HUD, also dunno how much CEF settings still make a difference since it was replaced on one of the major recent updates. But I wasted a lot of time to find out what works properly, icewm was actually quite a good test and ended up sticking to it dues to it not messing around with the game window, I do set the monitors with a xrand command that runs automtica on icewm start, also, some more icewm config settings/preferences.