kdemultiple-monitors
I have a Carbon X1 running Ubuntu 19.04 with KDE Plasma 5. When colleagues also running KDE plug an external monitor in, System Settings -> Display and Monitor will show all the displays. Mine however only show one box, even though the Primary Display dropdown lists No Primary Output, Laptop Screen and U28D590 (HDM1). This seems to mean I can mirror my output on both screens, but nothing else.
How do I get both displays to appear, so I can arrange them, and display different out on each.
KDE desktop metapackages
There are many ways to install the KDE desktop. The kde-standard (http://packages.ubuntu.com/raring/kde-standard ) doesn't have the KDE screen setup modules as dependencies. They can be installed later.
KDE screen setup modules
The new: Kscreen
:~$ apt-cache show kscreen
Package: kscreen
Priority: extra
Section: universe/kde
Description: KDE monitor hotplug and screen handling The KDE multiple
monitor support is trying be as smart as possible adapting the
behavior of it to each use case making the configuration of monitors
as simple as plugging them to your computer.
This package contains the modules and plugins for monitor hotplut and automatic screen handling.
Homepage:https://projects.kde.org/projects/playground/base/kscreen
The old: kde-workspace-randr
:~$ apt-cache show kde-workspace-randr
Package: kde-workspace-randr
Priority: optional
Section: universe/kde
Description: randr tools from kde-workspace Screen resize and rotate
tools from KDE Workspace.
Homepage: http://www.kde.org/
Both modules can be installed side by side. Both have own quirks: http://www.kubuntuforums.net/showthread.php?62632-How-do-I-undo-display-resolution-changes
Post-installation and removal Nvidia, I noticed a strange(and a good one at that) behavior. And that its that the GUI response in the second monitor has become much improved.
And I also noticed that the xorg.conf has a different setting, pasting it for your reference,
jpvel@jpvel-M11xR3:~/Downloads$ sudo cat /etc/X11/xorg.conf.04192015
Section "ServerLayout"
Identifier "layout"
Screen 0 "nvidia"
Inactive "intel"
EndSection
Section "Device"
Identifier "intel"
Driver "intel"
BusID "PCI:0@0:2:0"
Option "AccelMethod" "SNA"
EndSection
Section "Screen"
Identifier "intel"
Device "intel"
EndSection
Section "Device"
Identifier "nvidia"
Driver "nvidia"
BusID "PCI:1@0:0:0"
Option "ConstrainCursor" "off"
EndSection
Section "Screen"
Identifier "nvidia"
Device "nvidia"
Option "AllowEmptyInitialConfiguration" "on"
Option "IgnoreDisplayDevices" "CRT"
EndSection
I suspect that the existing nouveau driver seems to start honoring the configuration and appropriately instruct the graphics card to send the output to the external monitor. As
For those souls who tried using the DVI port or HDMI to VGA adapter, let me forwarn you, it does not work. As neutrino pointed out, the HDMI port is welded with Nvidia card in Alienware laptops
Edit from 2nd answer:
I went for the reinstallation and again tried using the latest Nvidia drivers from ppa:xorg-edgers/ppa for Nvidia-340, it ended up mucking the UI. So I decided to uninstall and live with the existing setup.
However, with the fresh installation, I am able to work with a dual monitor setup that is not perfect, but usable. I mirrored the displays and ensured that the intel's graphics driver could do the rendering(but it is lousy though I admit)
Best Answer
When multiple monitors display the same content, have the same resolution and are not unified, they are stacked exactly on top of each other in the GUI. Just drag the monitor in front to the side to reveal the other monitor(s):