"How much RAM do I need?" is the most common question in Minecraft hosting. The answer depends on four things: player count, server software, plugin/mod count, and world size. Here is how to figure out the right number.
How Minecraft Uses RAM
Minecraft servers use RAM for:
- Loaded chunks: Each chunk takes roughly 5-15 KB of RAM. A player with 10 chunk view distance loads about 441 chunks. That is 2-6 MB per player just for terrain
- Entities: Mobs, item drops, XP orbs. Each loaded chunk holds entities in memory
- Plugin data: Plugins like Dynmap, CoreProtect, and economy systems cache data in RAM
- Player data: Inventory, position, permissions, cached data per connected player
- Java overhead: The JVM itself uses 300-500 MB just to run. Garbage collection needs headroom above your actual usage
Quick Reference Table
Vanilla / Paper (No Mods)
| Players | Plugins | Recommended RAM | |---|---|---| | 1-5 | 0-5 | 2 GB | | 5-10 | 5-15 | 3-4 GB | | 10-25 | 10-20 | 4-6 GB | | 25-50 | 15-30 | 8-10 GB | | 50-100 | Any | 12-16 GB |
Modded Servers (Forge / NeoForge)
| Modpack Size | Players | Recommended RAM | |---|---|---| | Light (20-50 mods) | 1-5 | 4 GB | | Medium (50-150 mods) | 1-10 | 6-8 GB | | Heavy (150-300 mods) | 1-10 | 8-12 GB | | Kitchen sink (300+ mods) | 5-20 | 12-16 GB |
Modded servers need more RAM because mods add blocks, items, dimensions, and world generation that all live in memory.
The Real Bottleneck Is Not RAM
Here is what most guides do not tell you: past a certain point, adding more RAM does not help. Minecraft's biggest performance limit is single-thread CPU speed, not memory.
If your server has 8 GB of RAM and only uses 5 GB, upgrading to 16 GB changes nothing. Your TPS drops are caused by CPU load (entity processing, chunk ticking) not memory pressure.
Check your actual RAM usage before upgrading:
In-game with Spark installed:
/spark health
This shows current memory usage. If you are using 60-70 percent of your allocated RAM, you have enough. Below 50 percent means you are paying for RAM you do not use.
Do Not Over-Allocate
A common mistake is giving Minecraft too much RAM. Setting Xmx to 16 GB when your server uses 4 GB causes longer garbage collection pauses. The JVM has to scan a larger heap for unused objects. This can actually cause lag spikes.
Good JVM flags for a 4 GB server:
-Xms4G -Xmx4G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200
Set Xms and Xmx to the same value. This prevents the JVM from constantly resizing the heap.
For servers with 8 GB or more, use Aikar's optimized flags:
-Xms8G -Xmx8G -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
These flags are specifically tuned for Minecraft's memory allocation patterns.
What Actually Uses a Lot of RAM
Dynmap / BlueMap
Map rendering plugins cache tile data in memory. A BlueMap instance for a large world can use 500 MB to 1 GB of RAM by itself. If you run a map plugin, add 1 GB to your baseline.
CoreProtect
Block logging databases grow over time. CoreProtect caches recent data in RAM for fast lookups. On a busy server after months of play, this can use several hundred MB.
GeyserMC
Geyser translates between Java and Bedrock protocols in real time. Each connected Bedrock player adds roughly 50-100 MB of RAM overhead compared to a Java player.
World Size
A freshly generated world is small. After months of exploring, the world file grows to 5-10 GB or more. Chunks are loaded and unloaded dynamically, but a larger world means more I/O operations. This affects disk more than RAM, but the chunk cache grows with exploration patterns.
Signs You Need More RAM
- Server crashes with "OutOfMemoryError" in the console log
- TPS is fine but the server randomly restarts
- Spark health shows memory usage consistently above 85 percent
Signs You Have Too Much RAM
- Spark shows memory usage below 40 percent during peak hours
- Periodic lag spikes every 30-60 seconds (GC pauses on a large heap)
- You are paying for 16 GB but only 5 GB is used
How to Right-Size Your Server
- Start with the recommended tier from the tables above
- Run your server for a week with your expected player count
- Check
/spark healthduring peak hours - If memory usage stays below 60 percent, you can downgrade
- If memory usage hits 80+ percent, upgrade one tier
This saves money compared to guessing high and paying for unused resources.
Space-Node plans range from 2 GB to 16 GB, all running on AMD Ryzen 9 3900X processors with NVMe storage. Start with what you need and upgrade anytime through the panel. Check the plans here.
