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Understand RAM Usage
The Memory section in the Pterodactyl console panel can be misleading at first glance. Many users assume the displayed value reflects the RAM their Minecraft server is actively using, when in reality it represents allocated RAM, not live consumption. This often leads to unnecessary plan upgrades when the server is actually running fine.
This guide explains what that number actually means, and how to check the true current RAM usage of your server using in-game and plugin-based tools.
Understand the Memory Display in Pterodactyl
The Memory display on the server console displays how much RAM the Java Virtual Machine (JVM) has reserved from the container, not how much RAM your server is actively using at that moment.
- The value shown is the allocated (reserved) memory the server has available to work with.
- Certain plugins, mods, and modpacks are configured to allocate as much RAM as possible by default, which inflates this value.
- A consistently high memory value is not an indication of a problem on its own.
Check Actual RAM Usage with Spark
Spark is a performance profiler available as a plugin or mod for most Minecraft server platforms (comes by default in Paper or any of its forks). It provides detailed, accurate memory statistics directly from the JVM.
- Install Spark on your server (pre-installed in Paper and its forks; available for Spigot, Fabric, Forge, and more).
- Run the following command from the in-game chat or server console:
spark health --memory- The output shows the current heap usage, non-heap usage, and garbage collection statistics, which reflect the true RAM consumption of the server. Notice in the screenshot below that the memory usage is considerably lower than the value shown in the first screenshot, because the panel reports allocation rather than actual usage.
Check Actual RAM Usage with the RAM Bar
If your server runs Purpur or one of its forks, you can enable a built-in visual RAM bar that displays live memory usage above the hotbar. For other Paper-based forks, the same functionality is available through the Purpur Bars plugin.
- Ensure your server is running Purpur, a compatible fork, or has the Purpur Bars plugin installed.
- Run the following command in-game:
/rambar- A bar will appear at the top of the screen showing the current RAM usage.
Read the RAM Bar
- The bar fills up as the JVM uses more memory.
- When it nears the end, the garbage collector runs and the bar empties, which is expected behavior.
- On servers with low memory usage, the bar may stay mostly empty and only fill occasionally.
- A bar that continuously fills and empties even while staying red is a sign that the server is working as intended, as shown in the screenshot below (official screenshot from Purpur).
Troubleshooting
- The memory graph is at 100% and the server is crashing. This indicates the server is genuinely running out of RAM. Review your plugin/mod list, reduce memory-heavy features, or No access.
/spark health --memoryis not recognized. Ensure the Spark plugin or mod is installed and loaded. Check the console for load errors./rambarreturns an unknown command. Confirm the server is running Purpur (or a compatible fork) or that the Purpur Bars plugin is installed and enabled.- Memory usage stays high even when idle. This is expected JVM behavior. RAM is only released when the garbage collector determines it is necessary.
If you require further assistance, you can open a support ticket here.
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