Completely unusable in Ubuntu 20.04

Same here. New script works for me, external monitors are working now, but they are unsable. After connecting dock, cpu usage is above 100% and external monitors are laggy, unsable. Graphics cards: Radeon Vega 8 Graphics/Radeon RX 560X. Everything is working correctly on windows.

Same here. Brand new install of ubuntu 20.04 on a brand new dell xp13. Installed the 5.3.1 driver; it works, but glacially slowly - type a command in terminal, sit back, wait three or four seconds for it to display.

same issue for me also. I created a separate thread here without realising about this thread.

Same issue here after upgrade to Ubuntu 20.04 

Hi all, After upgrading Ubuntu from 18.10 to 20.04 and installing latest driver the performance is extremely poor. It is ok, if I extend the display to second screen. If I am using the second screen as single display, the performance absolutely unacceptable and you cannot work like this.

Update/workaround 

Ok, an update. If I plug my xp13 laptop with a fresh install of 20.04 into my dell displaylink dock (D6000) and *don't* turn off the laptop monitor, everything is fast and useable. It's only if you either use the display settings to turn off the laptop screen (as you normally would for a docked laptop configuration) or physically close the lid of the laptop that everything goes glacial. Not a perfect fix, but at least it makes things workable again.

Has anyone else found that any applications on the laptop screen itself are very slow (under wayland)? Code:

I'm seeing the exact same issues from a desktop machine. If I have one monitor plugged in directly, the second monitor plugged into the docking station works. If they are both plugged into the docking station, it is so slow as to be unusable. This behavior is different than previous releases of Ubuntu when I would have to change the pageflip Display setting in xorg.conf.d. Now, the screen draws OK, the mouse moves around just fine; however, you have to hover over an icon for several seconds before you can click it, and wait several seconds after you click it for the interaction to be registered. The same with the keyboard: even in a pico editor each key strike takes several seconds to register in the terminal. For me, the DisplayLink driver only works for 1 monitor and then only if I am directly plugged into my video card for my primary monitor. This is less than optimal for me.

Is internal laptop's screen turned off? I noticed that on my laptop too. But only when my laptop's screen is turned off. When the laptop's screen is turned on, everything works without any problem.