Very low performance with AMD Ryzen Pro 4750U

[Christian Groove]

Originally Posted by dominik.zogg

I bought a Club Dual 4k Dock (Displaylink):

I got to notebooks, one for work, one for private, both running Ubuntu 20.10
The first got a Intel® Core™ i7-10710U Processor and the dock works well.
The second got a AMD Ryzen Pro 4750U and the performance of the external sceens is very low.

Moving windows redraw that slow that it looks like wobbling, parts of the window are moved others aren't. Mouse cursor feels a bit more fluid, but far from usable.

If you own a notebook with an USB-C adaptor, you should better take a look at the USB-C specification, especially if it supports USB DP 1.2 or newer. In this case you might try to look for a MST Hub/Docking station instead of using the USB way.
For MST-DockingStation you should not need any additional driver, because it is a USB-DP feature, so there should not be any reason to rely on display-link anymore.

[devnull10]

This is STILL a problem. Clearly DisplayLink aren't bothered about this, however it seems to be affecting a lot of people. I'm more than happy to work with support etc to provide diagnostics to get this fixed.


PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3903 root 20 0 2295932 77432 11560 S 136.7 1.3 4:26.26 DisplayLinkMana

[mlabert911]

Was facing the same issue on a 3700U with Vega 8
Was able to get it working smoothly on Arch using a patch
https://github.com/pioto1225/evdi/tree/amd_vmap_texture

Installed evdi-amd-vmap-texture from the AUR and edited /etc/modprobe/evdi.conf like mentioned on the GitHub to get it working

Hope this helps

[devnull10]

Originally Posted by mlabert911

Was facing the same issue on a 3700U with Vega 8
Was able to get it working smoothly on Arch using a patch
https://github.com/pioto1225/evdi/tree/amd_vmap_texture

Installed evdi-amd-vmap-texture from the AUR and edited /etc/modprobe/evdi.conf like mentioned on the GitHub to get it working

Hope this helps

This also worked perfectly for me, It's a bit of a headache because it's lost when you update the kernel so you have to go through resigning the .ko file etc. However once it's done, it works perfectly.