Poor performance with low CPU usage

[Winged_Hussar5643]

When playing HOI4 I always seem to have performance problems (game speed, fps, etc) despite having what I think is a good PC (my hardware knowledge is limited). Any advice on what could be causing these issues would be appreciated as I'd love to play the game without the lag which always remains regardless of upgrades to my PC

Specs:

CPU: AMD Ryzen 7 3800X 8-core Processor

GPU: NVIDIA GeForce RTZ 2060 SUPER

RAM: 16 GB

In game CPU core usage:

 

[Kazakk]

The game is poorly optimized and only uses 1 core effectively.
You can lower the speed to 4, or even less if it's a big mod like BICE or Kaiserreich. I have the same CPU.

 

[Winged_Hussar5643]

The game is poorly optimized and only uses 1 core effectively.
You can lower the speed to 4, or even less if it's a big mod like BICE or Kaiserreich. I have the same CPU.

The problem is that even at speed 4 and below my fps still drops significantly