I was told to "allocate more RAM" to Minecraft, does this help the performance or anything? If it does what does it help? Right now I have 1GB of RAM allocated to minecraft, would increasing it to 2GB help?

EDIT: After reading the comments a lot of you think the game is running bad already, well it's not it's running fine max graphics, the only time I can't do that is if I'm recording, so if I increase my ram amount will it do better when I record?

  • I don't know about Minecraft specifically, but since it's written in Java, the extra RAM is likely used to cache code that's been compiled by the JIT (Just in Time) compiler. Of course, loading that code from RAM is going to be faster than recompiling it from scratch. Although to be honest, most code don't go over a few (hundreds) Megabytes, so maybe I was wrong...
    – Nolonar
    Oct 16, 2013 at 19:26
  • @Nolor Don't forget that it's also used for simply running the game, which can be a lot of memory for game objects and calculation storage. Oct 16, 2013 at 19:41
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    @Nolonar The RAM requested here is more like what SevenSidedDie mentioned. It is how much RAM is made available to the JavaVM for running the application. Requesting 2GB of RAM for the app will show the JavaVM actually using around 3.5-4GB of RAM as it does all the management and tracking of the overall virtual machine in general.. This is often a wall Minecraft players run into when trying to work out how much they have vs how much they want to allocate and how much Java needs to itself.
    – James
    Oct 16, 2013 at 21:20
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    What exact problem are you having when recording? Is it stuttering? Is the recording quality unacceptable? Does it make the game lag? There are too many things that could be the problem when you say "the only time I can't [use max graphics] is if I'm recording", so without a proper description of the problem there is no way to answer that edited-in question. Oct 17, 2013 at 15:34
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    @Bananaman Now that you know why people might say "allocate more RAM", I think you have to ask a fresh question for solving your recording lag issue. We need all kinds of things, like system specs, version numbers, exact FPS, and so on, which would completely change this question. Besides, more RAM allocated may not actually be the solution, so a separate question is even more important. Oct 17, 2013 at 17:19

3 Answers 3


Allocating more RAM to Minecraft can do two things:

  1. If the game's performance is being limited by a lack of available RAM, it will ease that possible performance bottleneck.

  2. If the game is crashing due to Java running out of RAM (either due to bugs or due to complex constructions/mods in a world), it will postpone or completely prevent the crash from happening.

Whether allocating more RAM does either (or both) of these depends highly on what the source of the performance problem is in the first place; your particular computer's configuration and components; the size of the texture's you're using (32×32 takes 4× the RAM the default textures do, 64×64 takes 16× the default, etc.); the details of your Minecraft world(s); and what mods (if any) you have installed.

The default amount of RAM set by the Minecraft launcher is 1GB. This is usually plenty, but spikes in RAM usage or unusual circumstances can make it inadequate. If the game is normally running OK on 1GB but it's having a few issues sometimes, doubling it to 2GB should be plenty. If doubling it doesn't help, then the problem may not be solvable simply by giving the game more RAM and you may need to address the problem at the source: removing demanding mods, reducing texture pack size, solving physical heat problems, upgrading system drivers, turning off background processes, making redstone contraptions more efficient, etc.


As always, @SevenSidedDie has given a most excellent, encyclopedic answer. I provide a simple anecdote.

A while back, (release 1.2 ??) I had a skeleton XP farm in vanilla Minecraft, that would crash minecraft whenever it got more than 300 skeletons trapped into it. (That number is from old memory, that's my best effort recollection.)

I bumped up memory to 4 Gig, and I've never had minecraft crash since due to excessive numbers of mobs. (It will get laggy, whenever there are more than 500 mobs around)

  • Oddness, that should not matter really... Even with a large texture pack the number of things using the textures should not really matter... (I mention textures because the resource packs are the biggest source of RAM usage variance between minecraft instances). In 1.6.2 I had over 1000 mobs yesterday (300 cows/chickens, the rest an assortment of skeletons, withers, zombies, creepers and witches) with only 2GB of RAM on both my server and client with no RAM related issues (The audio can be a pain but RAM wont help that).
    – James
    Oct 16, 2013 at 23:59
  • @James Interesting, I should have added a "YMMV" :) My incident above occurred around 1.2 timeframe, so that maybe things have since been cleaned up.
    – John
    Oct 17, 2013 at 15:58

Allocating more memory to Minecraft is a great way to avoid the Minecraft Has Run Out of Memory error, which is becoming less and less of a problem as the game is refined over time. Despite this, users can still encounter it if they set off big explosions or run big Redstone machines.

Anyway, when allocating Minecraft more memory you'll want to make sure you have the 64-bit version of Java installed, as you can't allocate any more than 4GB on a 32-bit version no matter how much you actually have on your machine!

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