u/Relevant-Button-9174

I have a save with 13k tracks, 3k buildings, 257 stations, and 238 trains, and I can't speed up the simulation to more than about 1 minute per second, compared to a blank save where I can skip several hours in a couple of seconds. Is this performance drop normal? My CPU usage is only about 30% on Intel i5 10400f + rtx3060. Has anyone encountered this kind of problem and knows what might be causing it?