Why give Minecraft more RAM?
Minecraft Java runs in Java, which can only use the memory it's given – and the official launcher gives it 2 GB by default. That's enough for vanilla, but modpacks, high-resolution texture packs, shaders and long render distances need more.
Signs that the game is short on memory:
- the game freezes for a moment every few seconds (Java clearing memory),
- a modpack hangs on the loading screen or crashes with an "OutOfMemoryError",
- the memory value on the debug screen keeps hitting close to 100%.
Press F3 in game and look at the top-right corner: Mem shows how much of the allocated memory is in use. If it often sits above 85–90%, more RAM will help. If it stays low, more RAM won't make the game faster – look at your graphics settings instead.
How much RAM should you allocate to Minecraft?
4 GB is plenty for vanilla, 6–8 GB suits most modpacks, and only very large packs need 10 GB or more. Never give Minecraft so much that Windows and your other programs run out.
| What you play | Recommended RAM |
|---|---|
| Vanilla, default settings | 2–4 GB |
| Vanilla with shaders or a high render distance | 4–6 GB |
| A few dozen mods | 4–6 GB |
| Big modpack (150+ mods) | 6–8 GB |
| Very large modpack (300+ mods) | 8–10 GB, or what the pack's page recommends |
Two rules of thumb:
- Leave at least 4 GB for your system. On a PC with 8 GB of RAM, give Minecraft 4 GB at most; with 16 GB, up to 8 GB is fine.
- More isn't always better. Allocating far more than the game uses can make Java's clean-ups longer and the stutters worse. Start with the table above and only go higher if F3 shows the memory filling up.
Modpack pages on CurseForge and Modrinth often list the recommended RAM – use that as your starting point.
How to allocate more RAM in the official Minecraft launcher
Edit the installation, open "More Options" and change -Xmx2G in "JVM Arguments" to the amount you want, for example -Xmx4G. The number is in gigabytes.
- Open the Minecraft Launcher and select Minecraft: Java Edition.
- Go to the Installations tab.
- Hover over the installation you play (for example Latest release or your Forge/Fabric profile), click the three dots and choose Edit.
- Click More Options.
- In JVM Arguments, find
-Xmx2Gat the start and change the number –-Xmx4Gfor 4 GB,-Xmx6Gfor 6 GB, and so on. - Click Save and start the game with that installation.
Only change the number after -Xmx. Leave the rest of the line alone – if you break it, the game may not start. The setting is per installation, so set it on the profile you actually play.
How to allocate more RAM in CurseForge
In the CurseForge App open Settings → Minecraft → Java Settings and move the "Allocated Memory" slider. This applies to all your Minecraft profiles.
- Click the gear icon (Settings) in the bottom-left corner of the app.
- Choose Minecraft in the game settings.
- Under Java Settings, drag Allocated Memory to the amount you want.
- Close the settings and start your modpack.
To give one heavy modpack more memory than the rest, open that profile, go to its Profile Options and turn off the use of the global memory setting, then set the RAM for that profile only.
How to allocate more RAM in the Modrinth App
Open the app's Settings, find the Java and memory options and set "Memory allocated" with the slider. That becomes the default for every instance.
- Click Settings (the gear icon).
- Go to the Java and memory section (default instance options).
- Set Memory allocated to the amount you want.
For a single instance: open the instance, go to its settings, choose Java and memory, enable a custom memory allocation and set the value there.
How to allocate more RAM in Prism Launcher
Go to Settings → Java and set "Maximum memory allocation". You can also override it for one instance.
- Click Settings in the top bar and choose Java.
- Set Maximum memory allocation (for example 6144 MiB for 6 GB). Leave the minimum low – it doesn't need to match.
- For one instance only: select the instance, click Edit → Settings → Java, tick Memory and set the values there.
Other launchers such as ATLauncher have the same setting, usually called maximum memory or RAM, in their Java settings.
Allocated more RAM and the game still lags?
RAM only fixes memory problems – frame drops usually come from the graphics card, the CPU or the server. Check these too:
- Lower the render distance in Video Settings – it's the single biggest performance setting.
- Add performance mods. On Fabric, Sodium (rendering), Lithium (game logic), FerriteCore (memory use) and Entity Culling are common choices. How to install them is in How to install Minecraft mods.
- Lag only on a server (blocks reappear, mobs freeze, slow chunk loading) is server lag. More RAM on your PC won't help – the server itself needs more resources or fewer heavy farms.
- Crashes with Exit Code 1 have many causes besides memory; see Minecraft Exit Code 1.
How much RAM does a Minecraft server need?
A vanilla or Paper server for a few friends runs on 2–4 GB, a modded server needs at least 6 GB, and a large modpack 8–12 GB. The number of players, plugins, mods and how much of the world is explored all add to it.
| Server | Players | RAM (rough guide) |
|---|---|---|
| Vanilla or Paper, no plugins | 1–5 | 2 GB |
| Vanilla or Paper with a few plugins | 5–15 | 4 GB |
| Paper with many plugins, public server | 15–40 | 6–8 GB |
| Fabric, Forge or NeoForge with a few dozen mods | 2–10 | 6 GB |
| Large modpack (200+ mods) | 2–10 | 8–10 GB |
| Large modpack, bigger group | 10+ | 10–12 GB or more |
Paper and Purpur run noticeably lighter than Vanilla with the same players, so they're the usual choice for plugin servers – see Minecraft server software. Pre-generating the map with Chunky also helps, because generating new terrain while players explore is one of the heaviest jobs a server does.
Minimum RAM for each server type on Spot.gg
On Spot.gg, Vanilla, Paper, Purpur and Folia servers start at 2 GB; Forge, NeoForge, Fabric and hybrid engines start at 6 GB; modpacks start at 6 GB and get their recommended RAM automatically. You can choose from 2 GB to 32 GB in 2 GB steps.
| Engine | Minimum RAM | Price from |
|---|---|---|
| Vanilla, Paper, Purpur, Folia | 2 GB | $3.90 / month |
| Fabric, Forge, NeoForge, Mohist, Arclight, Magma | 6 GB | $7.55 / month |
| Modpack | 6 GB, or the pack's recommended RAM if higher | $7.55 / month |
The RAM you choose is the memory Minecraft itself gets – Java's own overhead is covered on top, so you don't lose part of it to the system.
How to allocate more RAM to a Minecraft server
On a hosted server you change the plan's RAM in the panel; on a server you run yourself, you change -Xmx in the start command.
On Spot.gg: "Change parameters"
- Open your server in the panel and click "Change parameters".
- Pick the new RAM (and disk, if you need more space). The panel shows the cost of the change.
- Confirm. When you increase RAM, you pay only the difference for the days left in your billing period, and the new resources work right after payment. The server restarts to load them, so players briefly lose connection.
Lowering RAM is free and possible from 5 days before the end of the billing period (or after it has ended). It doesn't extend the server's time or give a refund for the rest of the period. During the free activation, you can change the parameters at any time at no cost.
Not sure more RAM is the fix? In the "Change parameters" window, "Server slowing down?" → "Ask the assistant" lets the AI assistant check what's actually straining the server – sometimes it's one farm or one mod, not memory.
On your own server
If you host the server yourself, the RAM is set in the start command or script with -Xmx (maximum) and optionally -Xms (starting amount):
java -Xms4G -Xmx4G -jar server.jar nogui
Leave enough memory for the operating system and anything else running on the machine, and remember that Java needs some memory beyond -Xmx for itself.
FAQ
How do I allocate more RAM to Minecraft?
In the official launcher: Installations → three dots → Edit → More Options, then change -Xmx2G in JVM Arguments to e.g. -Xmx4G. In CurseForge, Modrinth App and Prism Launcher there's a memory slider or field in the Java settings.
How much RAM should I give Minecraft?
About 4 GB for vanilla and 6–8 GB for most modpacks. Very large packs can need 10 GB. Leave at least 4 GB for your operating system.
Does more RAM increase FPS in Minecraft?
Only if the game was short on memory. If F3 shows plenty of free memory, more RAM won't raise your FPS – lower the render distance or add performance mods instead.
How much RAM does a Minecraft server need?
2–4 GB for a vanilla or Paper server with a few friends, 6 GB for a modded server and 8–12 GB for a large modpack. More players and plugins need more.
How much RAM do I need for a modded Minecraft server?
At least 6 GB, and 8–10 GB for a big modpack. On Spot.gg modpacks automatically get the RAM recommended for the pack.
Can I add more RAM to my server later?
Yes. On Spot.gg click "Change parameters" and pick more RAM – you pay only the difference for the days left in your billing period, and the server restarts with the new memory.
What does -Xmx mean?
It's the Java setting for the maximum memory the game or server can use. -Xmx4G means up to 4 GB.