SkyFactory 5 Server Hosting: Setup, RAM and Server Files

SkyFactory 5 is the fifth installment of the SkyFactory skyblock series, made by Darkosto and his team. You start in the void with next to nothing, and the whole progression runs on color: resources come from dye, gateways unlock the mobs you can spawn, and Create appears in a SkyFactory pack for the first time. This guide covers setting up a SkyFactory 5 server from the official server files, how much RAM it needs, and what the pack's own configs do once it runs on a server. SkyFactory 4 and SkyFactory One are further down.

Every SkyFactory 5 version number and file name below was checked on its CurseForge page and inside the 5.0.8 server files on 30 September 2026. The SkyFactory 4 and SkyFactory One details come from their own CurseForge pages and server files, checked the same day.

If you want a server with the sizing already worked out, see our SkyFactory 5 server hosting page.

SkyFactory 5 at a glance

The first files went up on CurseForge on 31 December 2024, and 5.0.2 on 2 January 2025 was the first one marked as a full release. Nothing newer than 5.0.8 has come out since March 2025, so a world you start today will not need a pack update every few weeks. Bug reports go to the DarkPacks/SkyFactory-5 tracker on GitHub, which the server README links to.

How much RAM a SkyFactory 5 server needs

The README in the server files says: "Recommended Min Memory is 4GB (You might be able to run it with less, but it's not optimal)". The user_jvm_args.txt in the same zip sets -Xmx4G, so a server started with the pack's own scripts never grows its Java heap past 4GB.

That 4GB is only the heap. Java needs memory for itself on top of it, so a 4GB plan running a 4GB heap has nothing left over. Count on the heap plus about 2GB:

The pack does not publish player counts, and we are not going to invent any. More players online and bigger automation both push memory up, so keep an eye on the memory graph in the panel and raise the heap before it runs full.

Your players need memory too. The CurseForge page asks for at least 6GB allocated to the game on the client, and Java 17.

How to set up a SkyFactory 5 server

Step 1: Download the server files

On the SkyFactory 5 CurseForge page, open Files, click 5.0.8 and look under Additional Files for SkyFactory_5_Server_5.0.8.zip. The regular SkyFactory5-5.0.8.zip is the client pack: a manifest and config overrides, no mods and no server setup.

The server zip contains:

• forge-1.20.1-47.4.0-installer.jar, plus Install.sh and Install.bat, which only run that installer with --installServer
• settings.sh and settings.bat, which only name the installer jar for the install scripts
• user_jvm_args.txt with the heap setting
• server.properties, server-icon.png and two README files
• the mods, config, defaultconfigs, scripts, global_packs and thingpacks folders

Step 2: Install Forge 47.4.0

On a Space-Node server, install Forge 1.20.1-47.4.0 from the panel first. On your own machine, run Install.sh on Linux or Mac, or Install.bat on Windows. Either way you end up with a libraries folder and the run.sh and run.bat start scripts. There is no server.jar to point at.

Step 3: Upload the pack

Upload everything from the zip over SFTP (FileZilla works) into the server's main folder, next to libraries. Keep the server.properties from the zip for the first start. It already sets allow-flight=true, so players using jetpacks or other flight items do not get kicked, and spawn-protection=0.

Don't copy the mods folder from your own CurseForge install. The client pulls 293 files from CurseForge, while the server files hold 264 mod jars, so start from the server zip.

Step 4: Java 17 and memory

Pick Java 17 in the Startup tab of the panel. The pack's troubleshooting README asks for a 64 bit Java 17.

If your server starts through user_jvm_args.txt (the Forge run.sh does), open it and set the heap to your plan's RAM minus about 2GB. On an 8GB plan that is:

-Xmx6G

The Forge run.sh reads that file and runs this line (anything you pass to the script, such as nogui, is added at the end):

java @user_jvm_args.txt @libraries/net/minecraftforge/forge/1.20.1-47.4.0/unix_args.txt "$@"

On Windows, run.bat runs the same line with win_args.txt and %* at the end. If you want garbage collector flags as well, they go in the same file; our Aikar's flags guide explains which ones.

Step 5: Accept the EULA

The first start stops because the Minecraft EULA has not been accepted. Open eula.txt, change eula=false to eula=true and start again. The next start loads all 264 mods, so give it time and don't restart halfway.

Step 6: Connect

Players install version 5.0.8 of SkyFactory 5 in the CurseForge app and add your server address in the multiplayer list. Their version has to match the server exactly.

What the server files already do

A few settings in the 5.0.8 configs matter on a server and are easy to miss.

Backups every 30 minutes

5.0.8 added Simple Backups, and it is switched on. It makes a full backup every 30 minutes while players are online, keeps the last 7 and deletes the oldest once the folder passes 25GB. Those backups land in the backups folder on the server's own disk, so they count against your plan's storage. The 6GB Standard plan has 40GB of NVMe, which a big world plus 25GB of backups can fill. Lower backupsToKeep or maxDiskSize in config/simplebackups-common.toml if that happens, and still take a backup from the panel before any big change. Our guide on backing up and restoring a world on Pterodactyl shows how.

Chunk loaders without a limit

config/chunkloaders-common.toml sets maxLoadedChunksPerPlayer = -1, which means no limit, and chunk loaders also do random ticks in the chunks they hold. A player's loaders only switch off after 7 days offline (inactivityTimeout = 10080 minutes). For a group of friends that is fine. On a public server, set a real limit per player, because every loaded chunk keeps ticking whether anyone is near it or not.

Shared progress for teams

Also new in 5.0.8 is Together Forever, which syncs advancements and game stages between players in the same team. SkyFactory 5 gates its progression through color stages, so this is how a group works through them together instead of each player unlocking everything alone.

Keeping the server fast

The main server tick runs on one thread. Create contraptions, machines and mob farms all add to that one tick, so single-thread CPU speed matters more than the number of cores.

spark is not part of the pack. Put the Forge 1.20.1 build of spark in the server's mods folder only (players don't need it) and run /spark profiler start when TPS drops, then /spark profiler stop after a few minutes. Our spark profiler guide shows how to read the result.

The shipped server.properties uses view-distance=10 and simulation-distance=10. Lowering simulation-distance to 6 or 8 cuts the number of chunks that tick around each player, which helps most once several players have their own builds spread out.

SkyFactory 5 lets players spawn mobs on demand once they complete gateways, and spawners can be upgraded. A farm with hundreds of mobs standing in it costs a lot of tick time, so agree on limits early on a shared server.

SkyFactory 4 and SkyFactory One servers

SkyFactory 4 still has far more downloads on CurseForge (over 14 million, against about 1.6 million for SkyFactory 5), but it has not been updated since December 2021. Here is how the three packs compare, taken from each pack's own server files:

All three READMEs call 4GB the recommended minimum, so the same rule applies: plan for the heap plus about 2GB.

SkyFactory 4 is set up differently. There is no user_jvm_args.txt. The heap sits in settings.sh or settings.bat as MIN_RAM (1024M) and MAX_RAM (4096M), and ServerStart.sh starts forge-1.12.2-14.23.5.2860.jar. Forge for 1.12.2 needs Java 8. Keep the shipped server.properties, because its generator-settings line selects the Sky Factory 4 world preset, and read the Multiplayer Instructions PDF in the zip for the island setup. Our SkyFactory 4 server guide has the details.

For SkyFactory One, the server README warns that some of its mods do not work on Java 16 or newer, so stay on Java 14 or lower.

Common problems

The server stops right after starting

Check the Java version first: 17 for SkyFactory 5, 8 for SkyFactory 4, 14 or lower for SkyFactory One. On a brand new SkyFactory 5 server, the first start also stops until eula.txt says eula=true.

The server only uses 4GB on a bigger plan

If your server starts through user_jvm_args.txt, that is the shipped -Xmx4G. Raise it as in step 4. If the panel's Startup tab also passes an -Xmx, make sure only one -Xmx ends up on the line that starts the server.

Players cannot join

Almost always a version mismatch. Server and players all need 5.0.8.

The disk fills up

Look in the backups folder. Simple Backups keeps up to 25GB there by default.

TPS drops after a few days

Automation and chunk loaders build up over time. Profile with spark, then limit chunk loaders per player if one base is loading far more than the rest.

Hosting SkyFactory 5 on Space-Node

Matching the RAM table above to our plans, at the Standard prices on the SkyFactory 5 hosting page:

• MC Lapis, 6GB, EUR 5.40 per month. Runs the pack as shipped with its 4GB heap.
• MC Diamond, 8GB, EUR 7.20 per month. Our suggestion, with room to raise the heap to 6GB as the factory grows.
• MC Special 1, 12GB, EUR 10.80 per month. For late game automation or a public server.

On the Standard tier these plans run on AMD Ryzen 9 3900X-class CPUs with DDR4 memory in the Netherlands, Germany, Poland, Canada and India. In the Netherlands, Germany, Poland and Canada you can switch to Premium, a Ryzen 9 9950X with DDR5, if you want the fastest single-thread performance. The USA (California and Virginia) has one hardware option with no tier to pick, the Ryzen 9 7950X3D with DDR5, and Singapore and Australia also have a single option, the Ryzen 9 5950X. NVMe storage and DDoS protection come with every plan. You pick the region in the plan selector before checkout, and the selector shows the price for that region. There are nine to choose from: Netherlands, Germany, Poland, Canada, USA California, USA Virginia, Singapore, India and Australia.

Running a different pack? Our modpack hosting page covers RAM for the other big modpacks.