I recently brought a brand new LG 32UN650-w 4K monitor (which is awesome by the way). At first I couldn’t go ahead of fullHD resolution but digging a bit I discovered
xrandr command and issuing
$ xrandr --newmode "3840x2160_30.00" 338.75 3840 4080 4488 5136 2160 2163 2168 2200 -hsync +vsync $ xrandr --addmode DisplayPort-0 3840x2160_30.00 $ xrandr --verbose --output DisplayPort-0 --primary --mode 3840x2160_30.00 --rate 30
I could get my maximum achieving resolution (due to hardware performance). That configuration was retrieved by
$ cvt 3840 2160 30 command.
Suddenly, after a reboot, this configuration not longer worked… I tried every combination without spinning a yarn. I’m currently running Fedora 34 with Gnome 40.4 up on Xorg server. Here my xorg.conf and here Xorg.1.log file.
My card is:
[AMD/ATI] Juniper PRO [Radeon HD 5750] (it should achieve 4K@30 using DP port) and monitor is connected using its DisplayPort cable.
I tried getting supported monitor combination resolution using different tools
No one of suggested ModeLine worked anymore. I also tried to boot different distro (Ubuntu 21, Fedora 35 beta) unsuccessfully. Windows 10 works like a charm at first shot. I switched from Wayland to Xorg (and back for test purpose), tried Xorg without configuration file (using default) and using a custom generated one, same result.
I’m running out of ideas at the moment. Thanks.