Factorio Forums

Since 0.15.37 I have been experiencing tick rate drop,I did not experience this before 0.15.37, be it game related or otherwise. It usually happens after a few minutes of play. The game tick slows down, bots fly slowly, significant delay between button press and game reaction. Zooming in seems to help as fewer things are being rendered. Saving the game, exit and reload have on occasion fixed it. But last time is crashed as I was saving.

One other note is that even the YouTube (or vlc) series running in the background are being affected. Audio starts stuttering and video slowing down or stopping.
mods
Bottleneck 0.8.5
Power Armor MK3 0.1.1
upgrade-planner 1.2.18

I loaded your save and there's nothing wrong with it. It runs at a perfect 60 FPS/60 UPS for me.

Additionally nothing changed game performance wise between 0.15.34/35/36/37 so any changes you're seeing are a direct result of you building/expanding the factory.