ATM9 vs ATM10 Server Requirements

Choosing between ATM9 and ATM10 for your server? The two modpacks have different hardware requirements, mod counts, and Java requirements. Here is the full comparison so you can plan your server resources correctly.

ATM9 vs ATM10: Quick Comparison

RAM Requirements by Player Count

ATM9 RAM Requirements

ATM10 RAM Requirements

These are our plan sizes, not an official ATM figure. The official ATM10 server files set a Java heap of -Xms4G -Xmx8G in user_jvm_args.txt, and Java needs memory on top of the heap, which is why our ATM10 server hosting starts at 12 GB. On a bigger plan, raise -Xmx in that file to fit your plan.

Java Version Requirements

ATM9 Java

ATM9 on Minecraft 1.20.1 officially supports Java 17 and Java 21. Java 21 is recommended for performance because it includes generational ZGC and improved virtual thread handling.

ATM10 Java

ATM10 on Minecraft 1.21.1 requires Java 21. Older Java versions will not launch ATM10. If you are running Java 17, upgrade before attempting to host ATM10.

Check your Java version:

java -version

Expected output for ATM10 compatibility:

openjdk version "21.0.x"

Performance: TPS Stability

Both packs target similar TPS stability. The practical difference comes from:

World generation: ATM10 world generation with 1.21 biomes is slightly slower than ATM9 on equivalent hardware. New players exploring new chunks will cause more brief TPS drops in ATM10.

Automation lag: Large Create factories or AE2 ME systems cause similar lag in both versions. The mod versions in ATM10 are newer and sometimes better optimized.

Chunk loading: ATM9 and ATM10 both benefit from pre-generating the world before opening to players. Pre-generate at least 3000 blocks radius to reduce explore lag. ATM10 does not ship Chunky, but NeoForge has a built-in command for this: /neoforge generate start 0 64 0 188 generates about 3000 blocks in every direction from 0, 0 (the radius is counted in chunks, and 188 chunks is about 3000 blocks). It needs permission level 4, so run it from the console or as a level 4 op.

CPU Requirements

Minecraft servers are largely single-threaded for tick processing. Clock speed matters more than core count. Both packs perform best on modern CPUs with high single-core performance.

Space-Node uses AMD Ryzen 9 hardware (9950X on Premium in the Netherlands, Germany, Poland and Canada; 3900X-class on Standard; 7950X3D in the USA; 5950X in Singapore and Australia). For Canada locations, the AMD Ryzen 9 3900X-class Standard tier provides solid single-core performance for modpacks.

Storage Requirements

The ATM10 server files are a 1.1 GB download and unpack to about 1.3 GB, before the NeoForge libraries and the world are added.

NVMe SSD is required for both. HDD or SATA SSD will cause noticeable chunk load lag with either pack.

Which is Easier to Host?

ATM9 is slightly easier to host because:

• Java 17 acceptable (more flexible hosting options)
• Fewer updates to keep up with: the latest ATM9 release, 1.1.1, came out on 12 October 2025, while ATM10 has had 16 releases so far in 2026
• Slightly faster world generation

ATM10 is worth hosting when:

• Players specifically want 1.21.1 content (new biomes, features)
• You already have 12+ GB RAM available
• Your group finished ATM9 and wants new progression

JVM Arguments for Both Packs

These arguments apply to both ATM9 and ATM10:

-Xms10G -Xmx14G
-XX:+UseG1GC
-XX:+ParallelRefProcEnabled
-XX:MaxGCPauseMillis=200
-XX:+UnlockExperimentalVMOptions
-XX:+DisableExplicitGC
-XX:+AlwaysPreTouch
-XX:G1NewSizePercent=30
-XX:G1MaxNewSizePercent=40
-XX:G1HeapRegionSize=8M
-XX:G1ReservePercent=20
-XX:G1HeapWastePercent=5
-XX:G1MixedGCCountTarget=4
-XX:InitiatingHeapOccupancyPercent=15
-XX:G1MixedGCLiveThresholdPercent=90
-XX:G1RSetUpdatingPauseTimePercent=5
-XX:SurvivorRatio=32
-XX:+PerfDisableSharedMem
-XX:MaxTenuringThreshold=1

Adjust -Xmx to match your available RAM. Leave at least 2-4 GB free for the operating system.

The official ATM10 server files ship -Xms4G -Xmx8G with G1 flags in user_jvm_args.txt. If you start the server with that file, raise -Xmx there to fit your plan.

Recommended Hosting Plans

For ATM9:

• MC Special 1 (12 GB) covers 1-8 players
• MC Special 3 (16 GB) covers 8-20 players

For ATM10:

• MC Special 1 (12 GB) for 1-5 players
• MC Special 3 (16 GB) for 5-15 players
• MC Special 4 (32 GB) for 15+ players

In the Netherlands, Germany and Poland these cost €10.80, €14.40 and €29.99 per month on Standard, or €21.99, €27.99 and €56.99 on Premium. You can compare all three on our All The Mods 10 server hosting page.

FAQ

Can I upgrade from ATM9 to ATM10 without starting over? No. ATM9 and ATM10 use different Minecraft versions and world formats. You cannot transfer worlds between them.

Is ATM9 or ATM10 more stable? ATM9 is more mature and has more community-tested configurations. ATM10 is newer and still receiving updates that improve stability. As of mid-2026, ATM10 is stable for dedicated servers.

Does ATM10 require more RAM than ATM9 on singleplayer? We have no reliable number that compares the two. The ATM team's general advice for its packs is to allocate 8-12 GB on a PC with at least 16 GB of system RAM, so start in that range with either pack.

Which pack has more content? ATM10 includes more mods and targets newer Minecraft content. ATM9 has a larger library of player guides and is better documented.

Can I run ATM10 on 8 GB RAM? Not as a server plan. The official ATM10 server files already set an 8 GB Java heap (-Xmx8G), and Java needs memory on top of the heap, so an 8 GB plan leaves no headroom. We recommend 12 GB for 1-5 players.

Related guides: ATM10 server requirements, ATM10 RAM calculator, ATM10 JVM arguments, All The Mods 10 server hosting