Hello,
I have a problem with long save loading times (close to 1 minute) on rpi 5 (nvme ssd), resolution 1280x800 (16:10 screen). Otherwise game is perfectly playable. Not as smooth as on PC, but it's using 300W less :). I have tried different hi res patch options, different rendering types in registry without success. On one site I've read that switching to different tab helps, but it didn't helped me. Maybe someone had similar problem.

works best on a DEC Alpha. Or if you can't get your hands on one of those, IBM POWER 11. Cheers.

The problem is not isolated to RPi, people with different hardware were complaining on the same issue. The only clue I've found is that it's not present on Proton 6 and early 7 versions. Will have to find manifest for that versions and compare them.
And I like RPi5 :) It's a very versatile platform.

This is what fixed all loading time for me. It was the DDRAW that is included in the HiRes patch which is outdated and installing it will glitch the S*** out of the display, but without it the game lag to death.

1. In HiRes patch, deactivate the DDRAW option and set software as renderer.
2. Download the most recent DDRAW from internet (Git)
3. Drop the .dll in the same folder of the arcanum.exe
4. Try to play a little, at the start it seems to be still slow (with some glitch) but then it starts to work properly

Hope that this will solve your problem!