Sky Factory 4 is one of the most enduring skyblock modpacks, combining automation mods like Applied Energistics 2, Mekanism, and Refined Storage with the classic "start on a floating island" format. Here is what you need to host it well.
What makes Sky Factory 4 different to host
Unlike combat-focused modpacks, Sky Factory 4's resource cost comes from automation, not entity spawning. Large factories full of machines, item transport pipes, and processing chains can generate heavy tick lag even with few players online, since the server has to process thousands of block updates and item movements constantly.
RAM requirements
| Players | Early game | Late game (heavy automation) |
|---|---|---|
| 1-3 | 4GB | 6GB |
| 4-8 | 5GB | 8GB |
| 8-15 | 6GB | 10-12GB |
Late-game Sky Factory 4 worlds with multiple large factories per player need noticeably more RAM than the early game, since the number of active machines and item entities scales up dramatically.
Setup steps
- Download the Sky Factory 4 server files from CurseForge
- Install the correct Forge version listed in the pack (Sky Factory 4 runs on Minecraft 1.12.2, similar to RLCraft, but with a different Forge build)
- Set Java to the version specified in the pack's server files
- Allocate RAM based on expected automation scale, not just player count
- Configure server.properties, then start the server and confirm no missing dependencies
Performance tips
- Use a server-side lag-checking tool like Spark to identify which chunk or machine type is causing tick lag
- Cap machine processing speeds in configs if a specific mod (like item pipes) is causing spikes
- Encourage players to keep large factories spread across multiple islands rather than stacking everything on one chunk
- Pre-generate the spawn area, even though Sky Factory 4 worlds are mostly void, spawn chunk loading still matters for performance
Choosing a host
Since Sky Factory 4's demands scale with automation rather than player count alone, plan for growth. Starting on a mid-tier plan and upgrading as factories expand is usually more cost-effective than overbuying RAM on day one. On Space-Node's Minecraft plans, MC Gold (5GB DDR4) covers early game groups, with MC Diamond (8GB DDR4) recommended once builds scale up.
For more modpack hosting comparisons, see our best ATLauncher modpacks guide.