SkyFactory 3 Server Hosting

FTB recommends 4 GB and that carries a small group through sieving, the first smeltery and early Roost coops. Once islands fill with Ender IO machines and large Refined Storage systems, 6 GB gives the garbage collector breathing room. Beyond that memory stops being the limit, because Forge 1.10.2 still ticks the whole world on one core.

What they build matters far more than how many of them log in. Each player takes a separate island and every island keeps its own sieves, coops and machines ticking, so load grows with automation rather than headcount. A tidy group runs fine on the recommended memory, while one person with a compressed sieving loop can drag tick rate down alone.

Build 3.0.21 is the final FTB release, so most servers install it and never move again. If you are coming from an older build, back up the world first, update the server and every client to the same build, then start the server once with nobody connected so the new mod versions write their configs before players load chunks.

You can add Forge 1.10.2 mods, and every player needs the same jar on their client or the handshake rejects them. Removing a mod is the dangerous direction: blocks and items it added vanish from the world, so machines built from them disappear along with whatever was inside. Take a backup before either change.

SkyFactory 4 moved to Minecraft 1.12.2 and introduced the prestige system, which locks parts of the tree behind points you unlock. SkyFactory 3 has none of that: everything is open from the first sieve, the mod list is smaller and the older Forge version is lighter on a server. Choose 3 for the classic uninterrupted grind.

Less than you would expect. Roost keeps birds inside a block rather than letting them wander around as entities, so a chicken heavy island is usually cheaper to tick than a farm full of loose mobs. The real cost on this pack sits with automated sieves and hammers chewing through compressed blocks every single tick.