Idea
Primary laptop will run DE with 1 screen (its own).
Second laptop is to be used as a secondary (extended) monitor for primary laptop.
Both laptops will run Linux.
Tested solutions and their issues
krfb-virtualmonitor:
Creates virtual display and runs a VNC server, exactly as desired.
Issue: Slow as hell. FPS become SPF even on 0.3ms 1Gbps point-to-point connection.
KDE Connect virtual display
Creates virtual display and runs an RDP server, exactly as desired.
Issue(s): Really needs that high quality connection to run reasonably well. That isn’t much of a problem, I can use a cable. The biggest problem is, no matter the settings, both with Remmina and KRDC the mouse pointer does not show up. Silly issue, but yeah.
Also, the Debian 13 KDE Connect package is too outdated to work with this, but I was able to use it in KDE Neon and Arch.
So, basically what I want exists, just with a major bug. Not seeing the mouse pointer is quite a problem.
Also, at first I hoped to use the already existing “network”, my phone’s hotspot. I can get 300Mbps and 3ms between phone and client. But between 2 clients? 400ms and with ping I see 1/3 of packets being duplicated.
So like a virtual KVM switch? Barrier was discontinued, but I think solutions like Synergy, Deskflow, or InputLeap still exist. There might be a better community suggested alternative to those as well.
This seems like it’s for sharing same keyboard and mouse between multiple computers. What I am looking for is for the secondary laptop just to act as a monitor. That’s it. It could just be a video stream of a virtual monitor.
Create virtual display, Run Sunshine on main PC, Moonlight on guest, it should work
What you want was very performant and easy doable with X11 (by its nature as a client/server architecture), but not with wayland. The additional Software layers on top of wayland will destroy performance and introduce all kind of issues.
Thats the price we have to pay for the shiny new things
Not sure what you mean about the mouse cursor not showing up. You mean you can interact with the mouse, but just see a cursor? Or no matter which direction you move the mouse the cursor doesn’t get there?
You sure after setting up the virtual display you’re going through the steps to setup the orientation of monitors?
What I mean is the mouse cursor isn’t there when I move it over there. Well, isn’t visible. It still interacts with objects.
Same as this person’s issue: https://discuss.kde.org/t/show-cursor-on-virtual-display-kde-connect-krdc/43421
Just to address the networking part…
Wifi is a 1:1 link, usually half-duplex (unless you’ve got something like a MuMiMo router) so you’ll transmit a block of video to the phone and then have to wait for the phone to transmit that block to the laptop, then repeat.
You don’t state the screen sizes, but I suspect you’ll only get decent FPS (I presume this is for gaming) with a cable as that will be full duplex.
For the application, maybe take a look at something like Deskflow
Solution is jetkvm or pikvm. Also reasonably cheap.



