Simple tip for less stuttering.

In windows explorer, go to:
C:\Users\[yourusername]\AppData\Roaming\The Creative Assembly\Attila\scripts
or
%appdata%\The Creative Assembly\Attila\scripts
and open the file
preferences.script.txt

In that file, find the following line:


And change the 0 to the number of threads or cores your CPU has available.
For exampe, in my case, using a Ryzen 7 5800x:


If you do not know how many cores your CPU has, press CTRL+Shift+Esc, open the "Performance" tab, and the CPU tab should then tell you all you need to know.

Thanks to dumpledops on Reddit for sharing this tip.
https://www.reddit.com/r/totalwar/comments/7c77w2/tw_attila_performance_tweaks/