It seems that support existed in KDE/Plasma workspaces in late 2014. https://www.phoronix.com/scan.php?page=news_item&px=MTg2NTY https://www.phoronix.com/scan.

It seems that support existed in KDE/Plasma workspaces in late 2014. https://www.phoronix.com/scan.php?page=news_item&px=MTg2NTY https://www.phoronix.com/scan.php?page=news_item&px=MTg2NTY Though if you follow the DP MST keyword there's still some corner cases being polished... https://www.phoronix.com/scan.php?page=search&q=DP%20MST https://www.phoronix.com/scan.php?page=search&q=DP%20MST https://www.phoronix.com/scan.php?page=news_item&px=DRM-Misc-Next-4.21-1 https://www.phoronix.com/scan.php?page=news_item&px=DRM-Misc... The Mesa drivers Ubuntu (and Debian, and many other distros) provide CAN be rather old. As you mentioned Ubuntu, follow the directions here to have a stack that's as updated as possible. https://github.com/ValveSoftware/Proton/wiki/Requirements https://github.com/ValveSoftware/Proton/wiki/Requirements I also tend to like checking Arhc Linux support page, but it doesn't seem to be helpful for this issue: https://wiki.archlinux.org/index.php/Radeon https://wiki.archlinux.org/index.php/Radeon