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
| Spec | ATM9 | ATM10 |
|---|---|---|
| Minecraft version | 1.20.1 | 1.21.1 |
| Mod count | 400+ | 430+ |
| Minimum server RAM | 8 GB | 10 GB |
| Recommended server RAM (5 players) | 12 GB | 14 GB |
| Recommended server RAM (10 players) | 14 GB | 16 GB |
| Java version | Java 17 or 21 | Java 21 |
| Mod loader | NeoForge | NeoForge |
| Storage required | 10-15 GB | 12-18 GB |
| World generation speed | Moderate | Moderate to Slow |
| Base TPS stability | Similar | Similar |
RAM Requirements by Player Count
ATM9 RAM Requirements
| Players | Minimum RAM | Recommended RAM |
|---|---|---|
| 1-3 (solo/small) | 8 GB | 10 GB |
| 3-6 players | 10 GB | 12 GB |
| 6-10 players | 12 GB | 14 GB |
| 10-20 players | 14 GB | 16 GB |
| 20+ players | 16+ GB | 20+ GB |
ATM10 RAM Requirements
| Players | Minimum RAM | Recommended RAM |
|---|---|---|
| 1-3 (solo/small) | 10 GB | 12 GB |
| 3-6 players | 12 GB | 14 GB |
| 6-10 players | 14 GB | 16 GB |
| 10-20 players | 16 GB | 20 GB |
| 20+ players | 20+ GB | 24+ GB |
ATM10 requires roughly 2 GB more RAM than ATM9 at every tier. The reason is ATM10 targets Minecraft 1.21.1 with NeoForge, which carries a larger base memory footprint than the 1.20.1 ecosystem.
Why ATM10 Needs More RAM Than ATM9
More mods: ATM10 added roughly 30 additional mods over ATM9, each contributing to the baseline memory usage.
New Minecraft version: Minecraft 1.21.1 has a slightly larger JVM heap baseline than 1.20.1.
Updated mod versions: Many mods like Create, Applied Energistics 2, and Mekanism were updated for 1.21 with additional features that increase memory use.
Chunk handling changes: NeoForge on 1.21 changed how chunks are handled in memory, which can increase peak RAM usage during exploration.
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 Chunky pre-generation before opening to players. Pre-generate at least 3000 blocks radius to reduce explore lag.
CPU Requirements
| Pack | Minimum Clock Speed | Recommended | Cores |
|---|---|---|---|
| ATM9 | 3.5 GHz | 3.8 GHz+ | 4+ |
| ATM10 | 3.5 GHz | 4.0 GHz+ | 4+ |
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 7950X (5.7 GHz boost) and Intel Core i9-13900K hardware for standard plans. For Canada locations, the Intel Xeon E-2274G provides solid single-core performance for modpacks.
Storage Requirements
| Pack | Install Size | World Size (30 days) | Recommended Disk |
|---|---|---|---|
| ATM9 | 8-12 GB | 5-15 GB | 50 GB NVMe |
| ATM10 | 10-15 GB | 6-20 GB | 60 GB NVMe |
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:
- Lower RAM requirements (saves cost at every tier)
- Java 17 acceptable (more flexible hosting options)
- Smaller install size
- Slightly faster world generation
ATM10 is worth hosting when:
- Players specifically want 1.21.1 content (new biomes, features)
- You already have 14+ 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.
Recommended Hosting Plans
For ATM9:
- Space-Node Game Tier 12 GB covers 1-8 players
- Space-Node Game Tier 16 GB covers 8-20 players
For ATM10:
- Space-Node Game Tier 14 GB covers 1-8 players comfortably
- Space-Node Game Tier 16 GB covers 8-15 players with headroom
View current plans and pricing on our Minecraft 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? Yes. Singleplayer ATM9 runs well at 8 GB. Singleplayer ATM10 needs 10-12 GB for a smooth experience.
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? On a dedicated server, 8 GB is too low for ATM10 with players. You may get it to load in solo testing, but expect crashes and lag with any active gameplay.
Related guides: ATM10 server requirements, ATM10 RAM requirements, ATM10 JVM arguments, All The Mods 10 server hosting
