What sort of computer are you running the game on, and what version of the game is it?
PC on Win10
Geforce GTX 1070 Ti
Hello I have the same issue. It appears globally after around 2000 players in-game. And it’s getting worse with the players increasing.
The simulation definitely starts being more CPU demanding when it’s run at maximum speed (which is something like 100x normal time) with a lot of players connected at once! Obviously exactly where you’re going to start seeing frame rate loss at high speeds is going to change a lot depending upon your computer hardware and similar. And double-especially if you do world edits while running at a high simulation speed.
I’m definitely still planning on doing some further optimisation passes on the game, but the game is doing a whole lot of simulation work at those high speeds!