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I want to configure different scales for my 4K monitor and the FHD, but it looks an impossible challenge.

Next my different tests and conclusions. A lot of things are not working, so I need to know (to decide) what to try to fix first.

Could you advise me about which path to take to get it working?

One important note: 30Hz is not enough refresh ratio. After a few hours, my eyes are killing me.

Conclusion.

  • BUG? Thunderbolt 3 cannot handle 4K higher than 30Hz.
  • BUG? HDMI is not working in Wayland. The monitor detects the connection but goes to sleep mode (No signal. Entering in power saving mode).
  • BUG? In X11 the Scale option is shared between all displays.
  • Fact: Display management is the worst parts of Linux.

Specs.

  • SO -> Ubuntu 18.04.2 LTS
  • Kernel -> 4.18.0-16-generic
  • Drivers -> Nvidia 390.116
  • Laptop -> Dell G5 15
  • 4K -> LG27UD68P-B
  • FHD -> HP 2311x
  • Video -> GeForce GTX 1060 with Max-Q Design/PCIe/SSE2
  • Video lspci -> NVIDIA Corporation GP106M [GeForce GTX 1060 Mobile]
  • Thunderbolt 3 -> Intel Corporation JHL6340
  • Thunderbolt 3 to HDMI adapter -> https://www.amazon.com/Cable-Matters-Multiport-Adapter-Ethernet/dp/B01M0K0DL2

Test 1

  • X11
  • 1 shared Scale option
| Connector   | Display   | Resolution | Hz  |
| ----------- | --------- | ---------- | --- |
| Built-in    | Built-in  | 1920x1080  | 120 |
| HDMI        | 4K        | 3840x2160  | 60  |
| Thunderbolt | FHD       | 1920x1080  | 60  |

Test 2

  • X11
  • 1 shared Scale option
| Connector   | Display   | Resolution | Hz  |
| ----------- | --------- | ---------- | --- |
| Built-in    | Built-in  | 1920x1080  | 120 |
| HDMI        | FHD       | 1920x1080  | 60  |
| Thunderbolt | 4K        | 3840x2160  | 30  |

Test 3

  • Wayland
  • HDMI does not work
  • 2 shared Scale options
| Connector   | Display   | Resolution | Hz  |
| ----------- | --------- | ---------- | --- |
| Built-in    | Built-in  | 1920x1080  | 60  |
| HDMI        | NO SIGNAL |            |     |
| Thunderbolt | FHD       | 1920x1080  | 60  |

Test 4

  • Wayland
  • HDMI does not work
  • 2 shared Scale options but 4K is not scaling :)
| Connector   | Display   | Resolution | Hz  |
| ----------- | --------- | ---------- | --- |
| Built-in    | Built-in  | 1920x1080  | 60  |
| HDMI        | NO SIGNAL |            |     |
| Thunderbolt | 4K        | 3840x2160  | 30  |
angelcervera
  • 936
  • I don't actually see a question. – guiverc Mar 25 '19 at 09:21
  • @angelcervera that's actually oh so normal. the whole point of wayland was to solve modern display problems. also what do you mean by HDMI does not work. like specifically for 4K or in general under wayland? is that hdmi cable 4k compliant? – tatsu Mar 25 '19 at 09:27
  • @guiverc I highlighted the question. – angelcervera Mar 25 '19 at 10:01
  • @tatsu 4 different tests, always using the same cable, same displays, etc. X11 detects the display connected to HDMI but Wayland is not. – angelcervera Mar 25 '19 at 10:03
  • huh, interesting. Does the problem persist with newer kernel and/or ubuntu 18.10? – tatsu Mar 25 '19 at 10:31
  • @tatsu Added kernel version to the post. It is the last LTS version of Ubuntu 18.04.2 Do you think that test with 18.10 is worth? – angelcervera Mar 25 '19 at 10:42
  • 1
    I really do. you can temportarilly create it as a dual boot, once you're done you can delete it a eat up the space it took back into your partition via gparted. – tatsu Mar 25 '19 at 11:01
  • Good idea. I will do it this evening or tomorrow. Does 18.10 containt the las versioni of the kernel (I think 5.*)? – angelcervera Mar 25 '19 at 12:09
  • it's turning out this is something of a real trend and a big deal : https://askubuntu.com/questions/1128827/ubuntu-18-04-2-lts-hdmi-monitor-not-recognized, https://askubuntu.com/questions/1083288/hdmi-not-being-read , https://askubuntu.com/questions/1077502/hdmi-disconnected-in-18-04 , https://askubuntu.com/questions/1128859/dual-display-not-working-after-disco-dingo-upgrade no I think (from this post : https://askubuntu.com/questions/1128520/microsoft-sculpt-mouse-scroll-wheel-not-working-with-kernel-5-x-on-ubuntu-18-10) that ubuntu 18.10 is still on 4.something not 5.* (except for 19.04) – tatsu Mar 26 '19 at 15:12
  • another similar one : https://askubuntu.com/questions/1129052/hdmi-port-not-showing-up-on-xrandr-broken-nvidia-drivers – tatsu Mar 27 '19 at 10:32
  • yet another : https://askubuntu.com/questions/1129109/lubuntu-18-04-no-video-output – tatsu Mar 27 '19 at 13:17
  • perhaps another? : https://askubuntu.com/questions/1129139/ubuntu-18-04-overscan-underscan-issues – tatsu Mar 27 '19 at 13:28

0 Answers0