Why Minecraft needs more than the default memory

Minecraft runs on Java, which sets aside a fixed amount of your computer's memory (RAM) when the program starts. By default, Java gives Minecraft only 1 GB of RAM — enough for small worlds and low player counts, but not for large modded worlds, high render distances, or servers with many players. When Minecraft runs out of its allocated memory, the game stutters, chunks fail to load, and you may see "out of memory" errors before a crash.

Allocating 8 GB tells Java to reserve that much RAM for Minecraft before you launch it. This is a one-time setting you change in your launcher, not something you adjust inside the game. The steps differ depending on whether you use the official Minecraft Launcher, MultiMC, or another third-party launcher.

Key Takeaways

  • Minecraft's default memory limit is 1 GB, which causes lag and crashes on larger worlds or with mods.
  • You allocate memory through your launcher settings before starting the game, not inside Minecraft itself.
  • The official Minecraft Launcher, MultiMC, and other launchers each have different menus for this setting.
  • Allocating 8 GB is safe if your computer has at least 16 GB of total RAM; allocate no more than half your system RAM.
  • After changing the setting, close and reopen the launcher completely for the change to take effect.

Allocating memory in the official Minecraft Launcher

Open the official Minecraft Launcher and look for the "Installations" tab at the top. Find the version you want to play (usually "Latest Release" or the name of a specific version), hover over it, and click the three dots that appear on the right. Select "Edit" from the menu.

In the edit window, scroll down to the "JVM Arguments" field. You will see a line of text that includes something like -Xmx1G. The "1G" means 1 gigabyte. Change this to -Xmx8G to allocate 8 GB. Do not change anything else in that line. Click "Save" and close the launcher completely, then reopen it before launching Minecraft.

Allocating memory in MultiMC

MultiMC is a third-party launcher popular with players who use mods. Open MultiMC and right-click the instance (the Minecraft version) you want to modify. Select "Edit Instance" from the menu.

In the instance editor, click the "Settings" tab on the left. Look for the "Memory" section. You will see fields for "Minimum memory" and "Maximum memory." Set the maximum to 8192 MB (which equals 8 GB). Leave the minimum at 512 MB or higher. Click "Close" to save, then launch Minecraft from MultiMC.

Allocating memory in other launchers

Launchers like Curseforge, ATLauncher, and Technic Launcher each store this setting in a different place. In Curseforge, open the Minecraft section, find your profile, click the three dots next to it, and select "Profile Options." Look for a "Memory" or "RAM" slider and set it to 8 GB. In ATLauncher, go to Settings, find the "Java/Launcher" tab, and change the "Maximum Memory" field to 8192. In Technic Launcher, click "Options" in the top right, then "Java Settings," and adjust the "Maximum Memory" slider.

If you use a launcher not listed here, search the launcher's name plus "allocate memory" or "JVM arguments" — most have documentation or community guides that show exactly where this setting lives.

How much memory is safe to allocate

Allocate no more than half your computer's total RAM. If your computer has 16 GB of RAM, 8 GB for Minecraft is appropriate. If you have 32 GB, you could allocate 8 to 16 GB. If you have only 8 GB total, allocate 4 GB to Minecraft and leave the rest for your operating system and other programs.

You can check your total RAM by opening Task Manager (Windows) or Activity Monitor (Mac), or by typing "System Information" into your search bar. If you allocate more memory than your computer has available, your system will slow to a crawl as it uses disk space as fake RAM — this is called "swapping" and makes everything worse, not better.

What to do if the change does not work

Close the launcher completely and reopen it. Many launchers cache settings in memory, so the new allocation will not take effect until you fully restart the launcher. If Minecraft still crashes or reports low memory, check that you edited the correct installation or instance — it is straightforward to change the settings for one version and then launch a different one.

If you see an error message about Java or memory when you launch, your computer may not have enough free RAM at that moment. Close other programs (web browsers, Discord, video players) and try again. If the problem persists, lower the allocation to 6 GB or 4 GB and test whether the game runs more stably.

When to allocate less than 8 GB

If you play vanilla Minecraft (no mods) with a normal render distance, 4 GB is usually enough. If you use a few mods or play on a small server, 6 GB is a safe middle ground. Allocate 8 GB only if you use many mods, play with a high render distance (16 chunks or more), or notice lag and crashes with less memory.

Allocating more memory than you actually need does not help — it just wastes RAM that other programs could use. Start with 4 GB, play for a few minutes, and watch the memory meter in your launcher or in-game. If it stays below 80 percent of what you allocated, you allocated enough.

Frequently Asked Questions

Will allocating 8 GB make Minecraft run faster?

It will stop Minecraft from running slower due to memory limits. If you were seeing lag spikes, stuttering, or crashes caused by running out of memory, more allocation fixes that. If your lag is caused by a slow graphics card or CPU, more memory will not help.

Can I allocate more than 8 GB?

Yes, if your computer has enough total RAM. Do not allocate more than half your system RAM. If you have 32 GB total, you could allocate 16 GB to Minecraft. If you have 8 GB total, do not allocate more than 4 GB.

What happens if I allocate memory I do not have?

Your computer will use disk space as fake memory, which is much slower than real RAM. This makes everything sluggish — Minecraft, your operating system, and other programs. Allocate only what your computer actually has available.

Do I have to allocate 8 GB, or can I use a different amount?

You can use any amount. Start with 4 GB for vanilla Minecraft, 6 GB for a few mods, and 8 GB or more only if you need it. Watch your memory usage in-game to see if you are using what you allocated.

Why does my launcher not have a JVM Arguments field?

Some launchers hide advanced settings behind a checkbox or button labeled "Advanced Options," "Show Advanced Settings," or "More Options." Look for that button first. If your launcher has no memory setting at all, check its documentation or community forums for the correct menu.