Because many people ask this question here's a little tutorial how to give Minecraft more RAM memory to work.
Normaly Minecraft works fine with his 1GB RAM. But if you allocatte more memory, you can better some situations:
More RAM for texture pack buffering (128x ++)
More RAM for singleplayer and multiplayer maps buffering (less reloading)
Better working with RAM intensive mods
Faster map rebuild
This tutorial requires that you've installed a full Java version, (Java SE) or Java Developement Kit (JDK, includes SE) on your system. Else it might not work right. Installing the right Java version (also important: 32/64 bit) often solves many problems.
"Minecraft runs out of memory" happens often while running it with the wrong Java version! The preinstalled Java on new Computers-Systems might not support this. If you don't have installed Java, get it here!
What do I have to do?
Since Minecraft version 1.6.X you can use the new launcher. With this, it is possible to integrate Java commands directly into the game. Here is what you have to do:
Download and execute the new launcher
In the section "Profile Selection" click on "Edit Profile"
Under "Java Settings (Advanced), activate "JVM Arguments" and add into the text area this argument:
Save this profile and execute Minecraft. You will always start with 2GB of RAM
Picture depending on the launcher version. It may look little different with a newer launcher
I want more RAM, not only 2GB!
You can adapt the numbers to your needings:
-Xmx is the maximum of RAM wich Minecraft can allocate.
-Xms is the allocated RAM at the beginning.
-Xms can also be omitted. As result Minecraft will not allocate all Ram at once, but as much as needet.
-Xms must not be greater than -Xmx!
and so on ... (but who realy needs more )
Notice: You can't give Minecraft more Ram than you have! Else you will recieve an Error!
32bit only supports up to 4GB system memory. Therefore most 32-bit based systems only support around 2GB for your games. The limit depends on the system, if you got an error, try less allocation.
Be sure to use the right and newest Java version (64bit on 64bit-OS-Systems is recommended).
How much RAM do I have?
Easiest way to see how much RAM is free, open the Task Manager and change to the Performance Tab. Look how much Physical Memory is available / free.
Note that other programs and your system also need RAM to work. For example if you run TeamSpeak or Firefox in background, you should leafe enough memory for this software to run.
Some numbers for example:
Windows Vista Home Basic: 512 MB RAM
Windows Vista Home Premium, Business, Enterprise, Ultimate: 1GB RAM
Windows 7: 1 GB RAM (32-Bit) or 2 GB RAM (64-Bit)
Windows 8 / 8.1: 1 GB RAM (32-Bit) or 2 GB RAM (64-Bit)
Linux: 1-2 GB
Skype: 256 MB
Teamspeak: 64 MB
Something doesn't work? You got an error?
First of all check on spelling mistakes. Also important: upper and lower case.
Be sure you've installed a the correct Java version.
Remove -Xms[RAM] and try again
Adjust the numbers, try both at the same level
Check if you've enough free RAM. Do you use 64bit (when greater than 4GB)?
You found a fault in the post? Something is missing? Tell it to me! Please post questions and suggestions in this topic and not via PM!
Doesn't seem to work for me. Here's exactly what I put: java -Xmx2048M -Xms2048M -jar "C:\Users\^^^^^\Desktop\Minecraft.exe" (erased my name) I do have the required RAM, but it just flickers the cmd screen, then nothing happens. Sorry if I'm missing something totally obvious, bit of a noob with this kind of stuff.
The difficult thing is: before cmd closes, he writes his problem, but then it closes a bit too fast .
If we knew what cmd wants to tell us, it would be easier to help. The only think I could tell now is the same like Animal: Be sure the path is spelled right and you have the Minecraft.exe file on your deskop (not a minecraft.ink link).
Try to look if you can capture a picture or something of the cmd. If you find "Error: Unable to acess jarfile Minecraft.exe" then the problem is that cmd doesn't find the file.