A while back I put together a modded server and I had to account for some "lower end" computers. It was around 52 mods (including all dependencies and performance boosting mods) but still managed to run pretty well for them, which I'm guessing was because the server handled most of the world generation and stuff.

If I were to expand on that modpack, what would cause the most RAM usage, lag, or lowered FPS on the client side? World generation? Adding mobs? Adding a lot of new items? I know, if anything, adding more mods will increase load times for sure.

*Machines not included, as we are not doing really any tech related content.

**I installed all performance boosting mods from here.