This just changed for me... but the hardware may matter, as I'm on Hades Canyon, using the amd gpu, not HD graphics. A few days ago I updated to the then-latest 4.19-rc2 (and wrote https://ubuntuforums.org/showthread.php?t=2400400 documenting exactly what I did). Using plain old X (no desktop) on my Hades Canyon, I now see a 16384 x 16384 limit: $ xrandr Screen 0: minimum 320 x 200, current 11520 x 2160, maximum 16384 x 16384 Three screens horizontally work. https://www.mail-archive.com/amd-gfx@lists.freedesktop.org/msg24954.html looks related.
I have not yet tested on HD graphics with the new kernel. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1714178 Title: Triple 4K monitor display failed (modesetting driver limited to 8192x8192) To manage notifications about this bug go to: https://bugs.launchpad.net/xorg-server/+bug/1714178/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs