How to Set Up an ATM10 Server: Server Files, RAM and Java 21

This guide sets up an All The Mods 10 server from the official server files. It works on your own machine and on any host that gives you SFTP access and a startup tab. The version details are for ATM10 8.2, the latest release when we checked on 24 September 2026.

If you would rather skip the setup, our All The Mods 10 server hosting starts at 12GB for EUR 10.80 a month: pick a plan by player count and install the pack with the modpack installer in the panel.

What you need

The official server files set an 8GB Java heap (-Xmx8G in user_jvm_args.txt), and Java needs memory on top of the heap. That is why we start ATM10 at 12GB. The full sizing, including CPU and storage, is in our ATM10 server requirements guide.

Step 1: Download the server files

Get them from CurseForge:

• Open the All The Mods 10 files tab
• Pick the version your players will use (8.2 was the latest on 24 September 2026)
• Download the server files, not the client pack: ServerFiles-8.2.zip under Additional Files

Do not build a server by copying mods from a client install. The client pack has mods the server files leave out on purpose.

Step 2: Upload them to the server

On a hosted server, connect over SFTP (FileZilla works) with the credentials from your control panel. The official ATM guide's advice for hosts is to set up a fresh NeoForge server on the pack's NeoForge version, 21.1.251 for 8.2, and then upload the files.

1. Extract the zip on your computer
2. Upload everything in it: startserver.sh, user_jvm_args.txt, the NeoForge installer and the mods, config, defaultconfigs, kubejs, datapacks and local folders
3. Leave server-ip in server.properties alone. The official ATM guide warns that changing it can stop the server from starting

Step 3: Set Java 21

ATM10 needs Java 21. On a panel you pick it in the Startup tab; on your own machine, install a Java 21 build and check it with java -version. The official start script stops with an error if Java is missing or older than 21. Our ATM10 Java version guide covers Java 25 and the install commands.

Step 4: Start it and give it your RAM

You do not need your own start script. The server files come with startserver.sh, which installs NeoForge on the first run and then starts it like this:

java @user_jvm_args.txt @libraries/net/neoforged/neoforge/21.1.251/unix_args.txt nogui

There is no server.jar. The memory and garbage collector flags live in user_jvm_args.txt, which ships with -Xms4G, -Xmx8G and Aikar-style G1 flags. Raise -Xmx to fit your server and leave a couple of GB free for Java itself: on a 16GB plan, something like -Xmx13G. If you leave it at 8G, the extra RAM you pay for sits unused.

Which flags to keep, and when Generational ZGC is worth a try, is covered in our ATM10 JVM arguments guide.

Step 5: Accept the EULA

The first start installs NeoForge (do not interrupt it) and then stops because the EULA is not accepted yet. Set eula=true in eula.txt and start again. The script restarts the server 10 seconds after any exit unless the environment variable ATM10_RESTART is set to false.

Step 6: Check server.properties

On the first start the script writes a server.properties with the pack defaults, but only if the file does not exist yet:

view-distance=8
simulation-distance=5
max-tick-time=180000

Start with those. With around 500 mods, every extra chunk of view distance costs noticeably more than on vanilla, so raise it in small steps and watch the tick time.

Step 7: Pregenerate the world

The pack ships no pregeneration mod, but NeoForge has a command built in, so you do not need Chunky:

/neoforge generate start 0 64 0 313

The last number is a radius in chunks, not blocks: 313 chunks is about 5,000 blocks from the center. The command needs permission level 4, so run it from the console or as a level 4 op. Check progress with /neoforge generate status and stop it with /neoforge generate stop. Let it finish before players join.

It only generates the dimension it runs in. From the console, use execute in for the others, for example:

/execute in minecraft:the_nether run neoforge generate start 0 64 0 100

Running it day to day

Do not strip mods. Every player needs the same pack as the server, so removing mods from the server means it no longer matches what players run. The official server files already leave out the client-side mods.

Item Clear is on. ATM10 ships Crash Utilities with Item Clear turned on: every 5 minutes it clears dropped items when there are more than 1000 on the ground, with chat warnings 20 and 5 seconds before. Tell your farm builders, or change it in config/crashutilities-server.toml.

Backups. The server files ship no backup mod. Schedule backups in your panel, or copy the world folder yourself before every change.

Scheduled restarts. Many admins of large modpacks restart once or twice a day. On a panel you can set that up as a scheduled task.

Updates. ATM10 updates can remove mods and change recipes. Back up first, test the new version on a copy, and only then update the live server.

Common ATM10 server problems

The server will not start or crashes straight away. Usually one of: not enough RAM, Java older than 21, the EULA not accepted yet, or a corrupted mod file from an interrupted upload. Read the console from the top for the first error.

TPS keeps dropping below 19. Use /neoforge tps to see the tick time per dimension, then profile with spark, which ships with ATM10, to find the mod or the build causing it. Our ATM10 lag fix guide goes through the usual causes.

It crashes during chunk generation. Check that -Xmx fits your plan, and pregenerate so the server is not generating terrain while players play.

Players cannot connect. Make sure the server finished starting (watch the console), that port 25565 or your assigned port is open, and that every client runs exactly the same ATM10 version. Better Compatibility Checker, which is in the pack, shows a tick or an X next to the server in the server list.

Paper or Purpur? No. ATM10 runs on NeoForge. Paper and Purpur are Bukkit-based and cannot load NeoForge mods.

Which plan fits

These prices are for the Netherlands, Germany and Poland; the plan selector shows the other regions. How many players a plan really carries depends on loaded chunks and running automation, so start with the RAM the pack needs and move up a size if TPS drops under load.

Where to host it

The plans in the table are on our All The Mods 10 hosting page. Every plan runs on NVMe storage with DDoS protection included. Standard plans use Ryzen 9 3900X-class CPUs with DDR4 in the Netherlands, Germany, Poland, Canada and India, and the Ryzen 9 7950X3D with DDR5 in the USA (California and Virginia). Premium plans run on Ryzen 9 9950X nodes with DDR5 in the Netherlands, Germany, Poland, Canada and the USA. Singapore has one tier on the Ryzen 9 5950X, and Australia sells Standard and Premium on the same 5950X. The CPU is shared on every plan, Premium included. You can pick any of the nine regions in the plan selector and the checkout keeps that region. You choose the Java version in the Startup tab and can edit user_jvm_args.txt in the file manager or over SFTP.