I want to get an idea of just how expensive physics simulations are

I have a heavy interest in physics simulations. I want to create my own.
I want to know how many particles are being simulated. I want to know how many calculations are being done. I want to know specs. Speed, Count, Precision. Etc.
I see a lot of videos on youtube, but none of them come with specs in a table comparing simulations right next to each other.
I want to get an idea of how many particles I can have in a complex simulation because I want to see how many particles I can have running in my own simulation.