How to use 3 external monitors on Ubuntu 17.10 Dell XPS 13 9360?

Question

Just bought a new USB Type C to 3 HDMI adapter: amazon link and it seems like my laptop sees all 3 monitors, but can't handle them all together.

I've tried different cables that work, and different inputs/monitors and everything works, except when all 3 together, Ubuntu sees them (I can change the primary display to any of those 3 external monitors) but only the built-in monitor works.

Is there anything specific I need to do in order to support 3 monitors at once?

---

Update

2 external + built-in:

$ xrandr --listmonitors
Monitors: 3
 0: +*eDP-1 1920/294x1080/165+0+1080  eDP-1
 1: +DP-1-1-2 1920/509x1080/286+0+0  unknown output 0x48
 2: +DP-1-1-1 1920/509x1080/286+1920+0  unknown output 0x47

3 external + built-in(Only the built-in monitor works):

$ xrandr --listmonitors
Monitors: 1
 0: +*eDP-1 3200/294x1800/165+0+0  eDP-1

When 3 external monitors are connected, the display settings shows all 3 monitors kinda visible, but not usable:

Regarding video graphics, Dell XPS 13 9360 has Intel® Iris Plus Graphics 640 (Kaby Lake GT3) which theoretically, is able to handle 3 monitors, but would that mean 3 additional monitors or 3 monitors in total? source

While I use ubuntu 17.10, I use Xorg (wayland seems to be buggy).

Solution 1

What you are trying--and which desktop you are using--is vague here. There are specific things to try, but I cannot tell what you are trying. My desktop environment is XFCE4 on Ubuntu 17.10 running the X11-based display. Not Wayland.

I have Dell Precision 5510 and a brand new USB-C dock. On the Dock itself, there are HDMI and DisplayPort jacks. I can get 3 monitors going if you count the laptop display and the 2 monitors. I have used 3 external successfully when they are plugged into separate jacks, not in a USB-C dock. I'm pretty sure you can get 2 external working via the usb-c, I suggest you try with that. Then worry about 3rd.

Here are things to try. Let us know what you see.

In terminal, run

xrandr --listmonitors

to find out if system really does see monitors. You can run xrandr to get a much more verbose listing. Right now, I'm not connected, and end of xrandr output is:

DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis) 
DP-2 disconnected (normal left inverted right x axis y axis) 
HDMI-2 disconnected (normal left inverted right x axis y axis)

If you see that, then 4 monitors would be possible. Right now, I have removed the nvidia proprietary drivers and I still do have success with 2 external monitors via the dock. I expect you can too.

However, configuring will be a problem. Even if system notices your monitors, it will not use them until you configure them. You could try CLI with xrandr, but I don't do that too often anymore. It is easier if you use the GUI for this. My favorite is "arandr", which has worked great for 3 years, until last week it failed to recognize the resolutions. I have no idea what broke it.

If arandr fails, there is a much improved program called Display in the XFCE4 settings. I believe it is adapted from the Gnome project, possible your desktop has it, or similar. It lists detected monitors. You click a button "active" separately for each one, it shows them in a tiny rectangle, and you can move them about in the screen to place them left and right. If your dock is like mine, those monitors will not work until you activate.

If (IF) you are using the NVIDIA proprietary drivers for X11, run the

nvidia-settings

program. You'll see what monitors it can detect. You'll see that you cannot get all 4 monitors in one X11 session, but you can get a pairs connected with each other. You will probably not be able to drag a window across all 3 monitors. nvidia-settings will offer to re-write /etc/X11/xorg.conf for you. Make sure you have a copy of the old one before saying yes. At one time (say 2010), I was knee deep in settings for Xinerama and Nvidia Twinview. If you start bumping up against very fine grained video configurations, take a step back. It is still possible to do that stuff, but the whole push in X11 setup is to let users ignore it.

I am a little distrustful of the USB-C device you have. Unless you know for sure it works with your computer, it may be trouble. I got this computer May, 2016, and tried to order a dock. Dell said "our dock does not work, you can't buy one." I waited until Nov 2017 to get one because that was the first time the firmware was compatible with Ubuntu Linux. It mostly works now, but not always. The USB poops out about 10% of the time and I have to unplug everything. If a monitor powers down to save power, the laptop often cannot wake it up through the usb dock.

If you try and need more help, write back with more information, including what kind of dock this is, the xrandr output, and which video driver you are using, It really is a different game if you run the Nvidia proprietary driver.

Oh, if you are in Ubuntu 17.10 with Wayland as graphic environment, then I have nothing to say. I'm avoiding it.

Solution 2

It's possible to enable three simultaneous displays on graphics for 3rd Generation Intel® Processors and newer.

See Enabling Three Independent Displays with Intel® Graphics Controllers.

Use arandr ( Another XRandR GUI) to configure the layout. Three external monitors are working for me with Lenovo X250 (HD Graphics 5500) in Ubuntu 18.04.

Turn laptop display off and turn external monitors on (2xDP adapter to mini DP, 1xVGA).

xrandr --output VIRTUAL1 --off
xrandr --output eDP1 --off
xrandr --output DP1-3 --off
xrandr --output HDMI1 --off
xrandr --output HDMI2 --off
xrandr --output DP1-1 --primary --mode 1920x1080 --pos 1080x840 --rotate normal
xrandr --output DP1-2 --mode 1920x1080 --pos 3000x840 --rotate normal
xrandr --output DP2 --mode 1920x1080_60.00 --pos 0x0 --rotate right

Turn external monitors off and turn laptop display on

xrandr --output VIRTUAL1 --off
xrandr --output HDMI1 --off
xrandr --output HDMI2 --off
xrandr --output DP1-1 --off
xrandr --output DP1-2 --off
xrandr --output DP1-3 --off
xrandr --output DP2 --off
xrandr --output eDP1 --mode 1366x768 --pos 0x0 --rotate normal

---

Notes

1. If the resolution of VGA is not detected properly, configure it manually

   xrandr --newmode "1920x1080_60.00" 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync xrandr --addmode DP2 1920x1080_60.00

2. (Update 05/2021) 3 monitors in Ubuntu 20.04 works fine with Dell XPS 13 9565 (Intel UHD Graphics 615) and i-tec Dual Display Docking Station. displaylink-debian is needed.

shell> xrandr --listproviders
Providers: number : 5
Provider 0: id: 0x47 cap: 0x9, Source Output, Sink Offload crtcs: 3 outputs: 5 associated providers: 4 name:modesetting
Provider 1: id: 0x14e cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting
Provider 2: id: 0x12c cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting
Provider 3: id: 0x10a cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting
Provider 4: id: 0xe8 cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting

Comments

[WinEunuuchs2Unix]

I picked a similar usb-c to hdmi adapter based on positive reviews. I notice reviews on the one you picked aren't very good in comparison. You might want to email vendor and discuss problems and possible free replacement?

[WinEunuuchs2Unix]

I should add I did extensive research to ensure my Dell based Skylake with nVidia 970M and Thunderbolt 3 would drive two external displays and built-in laptop display before purchasing single USB-C to HDMI adapter. I don't know about three external displays though.

[noreabu]

I fear that support of USB-C to multiple Displays is still some work in progress. I just did some research on USB-C docks with multiple Display connections options and the results and opinions were kind of mixed. I have a similar adapter (same company) with Mini-DP to 3xDP and it works pretty good in combination with a NVIDIA 960M, but only when everything is plugged in from bootup.

[Filip Luchianenco]

@WinEunuuchs2Unix which one did you buy instead? was it one for 2 displays?

[WinEunuuchs2Unix]

No I didn't buy the dual display model. It was single display as I already had external HDMI nVidia port built into laptop. This is the model.

[Vladimir Botka]

Recent Intel graphic cards by default support 3 monitors. Would you mind changing the title to "How to use 3 external monitors on Ubuntu"?

[Filip Luchianenco]

Thank you for a detailed answer! That gave me a lot of insights on how unusual it is to have 3 additional monitors. Please see the updated question with details you mentioned. But as a conclusion, I think I misunderstood the meaning of "supports 3 monitors", which would mean 3 per total, not 3 external monitors. So I guess the only way to handle 3 external monitors is to have 2 external in Display Port (usb type c) and one through Usb 3 with something that has it's own video card; I bet configuring that would be a pain as well.

[pauljohn32]

Good luck. Write if it works!

[Filip Luchianenco]

I guess I'll just give up on using 3 external monitors if it is not support by default. But I have coworkers who use such devices, and it works for them (aka macbook pro 2015 connected to 3 external monitors). Thank you

[pauljohn32]

If you have hardware as good as the macbook pro, I bet we could figure this out :)

[Filip Luchianenco]

thank you for your response. Well I wanted to have 3 additional monitors besides the laptop monitor. And the problem was that my laptop would "see" 4 monitors(built-in + external) but I wasn't able to set them right. Also, I wasn't sure if based on their description 3 monitors means in total or 3 additional external monitors.

[Vladimir Botka]

3 monitor total. I've added a link to Intel's support.

[Filip Luchianenco]

I see. Thank you that actually helps!