[2023] Game lags after being open for couple of hours - restart fixes it

Right click on eu4.exe , properties, compatibility. Tick "disable fullScreen optimisations" untick every other box in that dialog, Apply and exit.

Edit that settings.txt to say:

refreshRate=60
fullScreen=yes
borderless=no

vsync=no

Then in the launcher Game Settings menu, select fullScreen display mode.


Does that help? If not, Please report the temperatures of your CPU and video (GPU)
1/ before starting the game up and
2/ after say 30 minutes' play.
If your PC's vendor has given you no way of reading temperatures, install
SPEEDFAN http://www.almico.com/sfdownload.php