How to Host a Techopolis 3 Server

Start from 8 GB of RAM, not a guess. Techopolis 3 runs Create, Applied Energistics, refined pipes, and urban decoration content on NeoForge 1.21.1, and the modpack's own recommendation is the floor, not a buffer on top of it — undersizing here is the single fastest way to get a chunk-loading stutter the moment a power grid or factory line starts ticking.

Import the modpack directly instead of guessing from a client export. Techopolis 3 ships a server pack through its catalog listing, and installing from that rather than zipping up a client instance avoids client-only mods leaking onto the server and config mismatches between loader versions.

Watch the first boot all the way through. Because Techopolis 3 is a city-builder-first pack, the first startup needs to finish generating and registering every block and item tied to its transportation networks and infrastructure mods cleanly before you touch anything — a server that looks 'done' but is still indexing AE2 channels or Create contraptions can desync badly under load.

Only invite players once that first clean boot is confirmed. Letting people in while the world is still settling its power grid and automation registries is how city layouts end up with missing blocks or broken conveyor lines nobody can explain later.

Back up before any world import, loader update, or config change. A half-built city in Techopolis 3 represents hours of power grid wiring and factory layout work — losing that to a bad update is a much bigger cost here than in a flatter survival pack.