Modify EDID, so my screens work at 61Hz

Trying to fix some what high power draw of RX 7900XT(to make its memory run cooler).

XOrg

Put below config in /etc/X11/xorg.conf.d/09-displays.conf(also attached as file in /X11/09-displays.conf).

Section "Monitor"
	Identifier "DisplayPort-0"
	Modeline "1200p_61" 196.53  1920 2048 2256 2592  1200 1201 1204 1243  -HSync +Vsync
	Option "PreferredMode" "1200p_61"
EndSection

Section "Monitor"
	Identifier "DisplayPort-1"
	Modeline "1440p_61" 317.24  2560 2744 3024 3488  1440 1441 1444 1491  -HSync +Vsync
	Option "PreferredMode" "1440p_61"
EndSection

Section "Monitor"
	Identifier "DisplayPort-2"
	Modeline "1200p_61" 196.53  1920 2048 2256 2592  1200 1201 1204 1243  -HSync +Vsync
	Option "PreferredMode" "1200p_61"
EndSection

Then restart X session and from system settings set new resolution.

Wayland(Gnome/KDE)

In this case, there are 2 options. First is to pass video kernel parameter(but it does not work for me) and other is to modify EDID so it contains addidional resolution data.

Modifying EDID

https://askubuntu.com/questions/973499/wayland-how-to-set-a-custom-resolution

Testing

https://wiki.archlinux.org/title/Kernel_mode_setting#Forcing_modes_and_EDID

Links

https://davejansen.com/add-custom-resolution-and-refresh-rate-when-using-wayland-gnome/