That's a very peculiar thing - games that use the original Quake 1 engine stutter in window mode and the framerate drops to single digits on full screen. This happens also on sourceports like darkplaces and quakespasm. Same thing with Wrath Aeon of Ruin which is a new game but also uses darkplaces engine.
The rig is more than capable, I'm running Doom Eternal without any problems.
specs are Ryzen 5 2400g, a second hand rx 570 4gb, 32GB ram, SSD, win10, all drivers up to date
There was no issue running these games without the additional GPU - Ryzen alone had no issues. I suppose it's something with the GPU drivers or compatibility. I did a new clean driver reinstallation and it didn't help
Any clues for what might be the problem?