Running a server on multiple cores?

I have a 4 core intel j1900 processor but rust only uses a core which gives me poor performance in the fps of the server and very malfunction despite having 8gb of ram.
Is there any way to run run in more than one core or improve performance for that cpu.

 

And as long as I use the two cores because the load is only in one
cpu use:

 

Rust server use one core.
You can see that If you turn off hyper threading

 

The best thing to do for rust servers is find a processor with 3.5GHz plus, and to not focus on cores all that much. From what I've been told, you can run a server efficiently on a simple duo core processor as long as its got a nice clock speed.

 

Why does my server go from this:


To this other:


I need to know why this happens besides the server fps down and ay lag