I have this monitor: https://www.lg.com/us/support-product/lg-32UD59-B .
And this laptop: https://www.msi.com/Laptop/GS65-Stealth-9SX-GTX .
It has a GTX 1660 Ti.
I connect them through Displayport. For some reason, HDMI does not work, but that might be the screen’s fault.
Using Nvidia’s driver (430.86) on Windows, 4k @ 60Hz works fine.
Using Nvidia’s driver (430.26) on Ubuntu 19.04, 4k only works at 30Hz. The 60Hz option is selectable in nvidia-settings, but the monitor screen just goes black once applying it.
A few oddities:
The monitor has an “Enable Displayport 1.2” option. If it is enabled, the 4k@60Hz resolution shows up on xrandr (and thus is selectable in the GUI through nvidia-settings and Gnome’s display settings). If I disable it, only 4k@30Hz shows up. However, on Windows, the monitor is only even detected if that option is DISABLED, and 4k@60Hz then works fine, which is weird.
I’ve spent already a few hours going through possible solutions, but couldn’t find anything that works. A few things I tried/didn’t try:
Installed lightdm. With the default display manager (gdm), the monitor wasn’t even detected by xrandr.
Manually adding a new 4k@60Hz option through xrandr newmode, addmode etc. Fails with “X Error of failed request: BadName (named color or font does not exist)”. I’ve read that the newer nvidia drivers stopped supporting manual xrandr commands, but I can’t confirm if that’s true.
Custom EDID. I haven’t tried this since my monitor’s EDID seems fine (I can paste the decoded version here if useful), showing 4k@60Hz and appropriate pixel clock (something around 500Mhz, more than enough).
A strange virtual splitting of the monitor into 2 (or 4?) virtual monitors of lesser resolutions through a custom xorg.conf file. I haven’t tried this either since even exporting a xorg.conf file directly through nvidia-settings and placing it in /etc/X11 results in a black screen after reboot.
I’m available to post whatever logs or debug stuff you think might be useful.
EDIT 1 Added nvidia-bug-report.log.gz.
nvidia-bug-report.log.gz (1.03 MB)