To allocate more RAM in CurseForge, open the launcher’s Settings gear icon, go to Minecraft under Game Specific, and drag the Allocated Memory slider. This guide covers both the global setting for all profiles and a per-modpack override, so you can fix lag, stuttering, and crashes no matter which modpack you run.
Why allocate more RAM in CurseForge?
Minecraft modpacks, especially large ones, quickly exhaust the default memory limit. When that happens, the game stutters, chunks fail to load, and you may crash to desktop. Increasing the RAM CurseForge gives to Java lets the game hold more world data, entities, and mod assets in memory, which smooths out gameplay and prevents those sudden shutdowns. Below you’ll find two ways to adjust it: one that applies to every Minecraft profile you launch, and one that lets you set a custom amount for a single modpack.
Check your available system RAM
Before you change anything, know how much total memory your computer has. On Windows, press Ctrl+Shift+Esc to open Task Manager, go to the Performance tab, and click Memory. On macOS, click the Apple menu and choose About This Mac to see the installed memory. The rule is simple: leave at least 2-3 GB free for Windows or 4 GB free for macOS. If you allocate everything to Minecraft, your operating system and background apps will slow down or freeze.
Method 1: Allocate more RAM globally for all profiles
This is the quickest way to raise RAM for every Minecraft profile you launch through CurseForge. It’s ideal if you play multiple modpacks and want a single baseline.
- Open the CurseForge launcher and click the Settings gear icon in the bottom-left corner.
- In the left pane, select Minecraft under the Game Specific category.
- Scroll down to the Java Settings section on the right side.
- Under Allocated Memory, drag the slider to your desired amount (for example, 6 GB).
Changes save automatically, so you don’t need to click any button. The next time you launch any Minecraft profile, it will use the new memory amount.
Method 2: Allocate custom RAM for a specific modpack
If one modpack needs more memory than your global setting, or you want to keep other profiles lean, use the per-profile override. This is especially useful when a heavy pack demands 8 GB while your vanilla profiles only need 3 GB.
- Go to the My Modpacks tab in the CurseForge app.
- Find the modpack you want to change, then click the three dots (Context Menu) next to the Play button.
- Choose Profile Options from the menu.
- Toggle Custom RAM Allocation on, then drag the slider to the amount you want.
- Click Done to save the setting for that modpack only.
This override stays active until you turn it off or change it, so you can tweak each pack independently without affecting others.
How much RAM should you allocate?
Start with your modpack’s size. For vanilla Minecraft, 2-4 GB is typically sufficient. Lightly modded gameplay usually runs well with 4-6 GB. Heavy modpacks, those with hundreds of mods, shaders, or large terrain generation, often require 6-10 GB or more. Don’t go over 10-12 GB for most cases. Allocating too much RAM can actually cause more lag and longer stutters because Java’s garbage collection process spends more time cleaning up memory, which pauses the game. Also, keep in mind that a 64-bit Java runtime is required to allocate more than 4 GB; modern CurseForge versions include and use the correct 64-bit Java by default, so you don’t need to change anything there.
What about Minecraft Bedrock Edition?
Manual RAM allocation only works for Minecraft Java Edition. Bedrock Edition manages its own memory automatically and cannot be adjusted through CurseForge or any other launcher. If you’re playing Bedrock and seeing performance issues, the cause isn’t RAM allocation, it’s likely your device’s hardware or background processes.
Related RAM guides
If you use other game launchers, the same memory-tuning logic applies elsewhere. For example, you might want to allocate more RAM to tmodloader if Terraria mods keep crashing, or allocate more RAM to stardew valley when running heavy farm mods. On the system side, you can clear RAM on a Chromebook to free up memory before launching a game, or increase RAM on a tablet if you’re playing on mobile hardware. And if you’re curious about Java versions, the TModLoader 64-bit vs 32-bit java memory limit explains why 64-bit is required for large allocations. For a broader overview, check our main guide on how to increase RAM for any application.
