One person who had this problem said disabling anti-aliasing in the options helped, another set the option in their Radeon pro to 'force game process high priority'.
I ran into this problem once (FPS drop on conversations, restored by quicksaving), after my computer had been on for several days and I had a few more than the usual background programs running. Rebooting fixed that, and it hasn't occurred again.
If you email supportdos@larian.com, with a description of the problem (or link to this post) and the report.zip file generated by the
D:OS support tool (for the PC version), I'll add that to the bug report for this issue. That may help narrow down the cause of the problem, and will at least remind the programmers about it and confirm it is still an issue in the latest version.
The report will contain system and game information, as well as your saved games. To reduce the file size, you can delete all but maybe one save from the zip.
