[Java] Tutorial: Giving Minecraft more RAM

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Post 06 Jul 2013, 17:22 

Giving Minecraft more RAM

There are a few things to keep in mind before you start:
  1. You need to have a 64bit OS and 64bit Java to use more than 2GB of RAM.
  2. When selecting your maximum RAM to give to Minecraft it can only be the max of what your system can handle AFTER taking in to account how much memory your Operating System requires.
    • Typically the max will be 512MB to 1024MB less than your system's capacity.
  3. You shouldn't assign more RAM than Minecraft actually needs to run smoothly.
    • e.g. if Minecraft will run fine with 3GB of RAM don't allocate 6GB just because you can.
  4. If you've assigned PermGen this is added on-top of the RAM you assign to Minecraft.
    • e.g. if you assign 2GB of RAM to MC and 256MB of PermGen that equals 2.25GB of RAM total.
    • Note: Java 8 and over no longer has PermGen at all.
If you need to find out how much RAM your computer has you can follow the guides on this page for Windows or Mac.

Linux users can type the following in to terminal and divide the result by 1,024,000 to convert it to GB:

Code: Select all

grep MemTotal /proc/meminfo

The Official Minecraft Launcher

Show Newest Launcher
  1. Open the Launcher and click "Minecraft: Java Edition" on the left to show your installations
  2. Hover over the installation you want to modify and click the ··· icon on the right and in the menu that appears click "Edit"
  3. In the "Edit installation" window that appears click "More options" at the bottom
  4. In the area that appears find "Java arguments" and edit the part that says -Xmx2G to a new setting e.g. -Xmx4G
  5. Click Save and then launch your game as normal
Image Image
Image Image


Show Old "New" Launcher
  1. Open the Launcher and click the ≡ in the top right
  2. Click "Launch Options" and then enable "Advanced settings"
  3. Select the profile you want to change the settings for
  4. Enable "JVM arguments"
  5. Edit the part that says -Xmx2G to new setting e.g. -Xmx4G
  6. Click Save and then launch your game as normal
Image


Show Old Launcher
Open the Launcher and click "Edit Profile" > Check the "JVM Arguments" box and type in the amount of RAM you want, e.g. -Xmx4G (you can also type -Xmx4096M) to give Minecraft 4GB > Click "Save Profile"

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MultiMC

Show
MultiMC is a free, open source launcher for Minecraft. It allows you to have multiple, cleanly separated instances of Minecraft (each with their own mods, texture packs, saves, etc) and helps you manage them and their associated options with a simple and powerful interface.

  1. Right click your instance
  2. Select "Edit Instance" from the menu
  3. Check the "Memory" box
  4. Set "Minimum memory allocation" and "Maximum memory allocation" to desired limit
Image

Feed the Beast, Technic, AT Launcher, VoidLauncher

Note: All of this information was correct for each launcher at the time of writing.
Show
Modpack launchers generally have a setting to change the RAM easily via a dropdown or slider.

Feed the Beast

Open the launcher > click Options > adjust the "RAM Maximum (MB)" slider:
Image

Technic

Open the launcher > click Options > adjust "Memory to allocate" dropdown:
Image Image

ATLauncher

Open the launcher > click Settings > adjust "Memory/RAM" dropdown:
Image

VoidLauncher

Open the launcher > click Options > uncheck "Let java decide optimal values." > specify "Max" RAM
Image


Changelog
Show
08 August, 2019: Added instructions for the newest Minecraft launcher.
24 October, 2018: Tidied up the thread, mainly to simplify the information a bit.
18 January, 2017: Added Minecraft New Launcher
29 September, 2015: Added note about not allocating more RAM than necessary
22 September, 2014: Added info about finding amount of RAM in system
08 August, 2014: Added some info about PermGen
15 June, 2014: Renamed Feed the Beast, Technic and AT Launchers to Feed the Beast, Technic, AT Launcher, VoidLauncher and added VoidLauncher
08 March, 2014: Updated Minecraft Launcher image
26 October, 2013: Renamed Feed the Beast and Technic Launchers to Feed the Beast, Technic and AT Launchers and added ATLauncher
2nd July, 2013: Added MC Launcher section
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Post 25 Jul 2013, 13:52

it wont let me go higher than 1 gigabyte pls help!!!
-takenyadown
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Post 25 Jul 2013, 17:04

takenyadown wrote:it wont let me go higher than 1 gigabyte pls help!!!
If you're on Windows press the Windows key and R together. In the box that appears type dxdiag (click OK if a warning about drivers appears).

In the next window that opens it'll have a line that reads "Memory:....". What does that say?
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Post 29 Jul 2013, 22:54

HanFox wrote:
takenyadown wrote:it wont let me go higher than 1 gigabyte pls help!!!
If you're on Windows press the Windows key and R together. In the box that appears type dxdiag (click OK if a warning about drivers appears).

In the next window that opens it'll have a line that reads "Memory:....". What does that say?
it says "10240MB RAM
-takenyadown
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Post 31 Jul 2013, 07:26

takenyadown wrote:
HanFox wrote:
takenyadown wrote:it wont let me go higher than 1 gigabyte pls help!!!
If you're on Windows press the Windows key and R together. In the box that appears type dxdiag (click OK if a warning about drivers appears).

In the next window that opens it'll have a line that reads "Memory:....". What does that say?
it says "10240MB RAM
So that's 10GB? Little bit of an odd amount...

If you really do have 10240MB of RAM you may need to make sure you may want to try reinstalling 64bit Java and see if that makes it recognise the amount of RAM you have.

However, if you do only have 1024MB that's 1GB so you'll not be able to assign more and will have to use lower resolution textures.
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Post 31 Jul 2013, 17:06

HanFox wrote:
So that's 10GB? Little bit of an odd amount...

If you really do have 10240MB of RAM you may need to make sure you may want to try reinstalling 64bit Java and see if that makes it recognise the amount of RAM you have.

However, if you do only have 1024MB that's 1GB so you'll not be able to assign more and will have to use lower resolution textures.
I do have 10240MB, but how do I reinstall java 64? and I have it but minecraft says I don't. (ever since I got the new launcher) If you have an official download and installation tutorial, that would be great, thanks!
-takenyadown
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Post 31 Jul 2013, 17:14

You uninstall Java like any other program. Start Menu > Control Panel > Uninstall a Program > Select Java and Remove. Make sure you remove all instances of Java.

Then get a fresh Java install from: http://www.oracle.com/technetwork/java/ ... 80261.html

Make sure to download the Windows x64 exe.

If that doesn't work you'll have to have a search in Google for specific reasons.
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Post 31 Jul 2013, 17:23

HanFox wrote:You uninstall Java like any other program. Start Menu > Control Panel > Uninstall a Program > Select Java and Remove. Make sure you remove all instances of Java.

Then get a fresh Java install from: http://www.oracle.com/technetwork/java/ ... 80261.html

Make sure to download the Windows x64 exe.

If that doesn't work you'll have to have a search in Google for specific reasons.
thanks

-- 31 Jul 2013, 17:26 --
HanFox wrote:You uninstall Java like any other program. Start Menu > Control Panel > Uninstall a Program > Select Java and Remove. Make sure you remove all instances of Java.

Then get a fresh Java install from: http://www.oracle.com/technetwork/java/ ... 80261.html

Make sure to download the Windows x64 exe.

If that doesn't work you'll have to have a search in Google for specific reasons.
which one?
[table][tr][td] Windows x64[/td][td]31.61 MB [/td][td]Image jre-7u25-windows-x64.exe[/td][/tr][tr][td] Windows x64[/td][td]41.69 MB [/td][td]Image jre-7u25-windows-x64.tar.gz[/td][/tr][/table]
-takenyadown
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Post 01 Aug 2013, 17:50

takenyadown wrote:which one?
The exe... like I said.
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Post 01 Aug 2013, 20:40

HanFox wrote:
takenyadown wrote:which one?
The exe... like I said.
ok oops, I skimmed through it, I don't pay attn that much, I will now

-- 01 Aug 2013, 20:42 --

it worked!
-takenyadown
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