If you are using a 64-bit operating system then an often highly effective way of improving the performance of Minecraft and avoiding the Minecraft Has Ran Out of Memory crash is to install 64-bit Java.
The 64-bit Java is a much newer, cleaner and faster runtime environment for Minecraft to operate within. Because of this many users experience dramatically increased FPS and all round performance after installation.
Making Minecraft use the 64-bit version of Java will improve the amount of RAM available to run Minecraft itself as your computer will require less to run Java.
Before we jump into installation we need to know if you are running a 64-bit operating system. Doing this is nice and easy. One way to tell is by checking whether your computer came with Internet Explorer 64-bit installed as default.
Another is to open the start menu and right click on “Computer” and select “Properties”. Under this menu will be a heading of “System”, which has a section titled “System Type” which will specify whether you are running a 64-bit or 32-bit OS. Check out this video for more help.
Now, if you’ve determined that you have a 64-bit OS then head to this link and download and install “Windows Offline 64-bit”:
In order for your system to know which Java to use you must right click your Minecraft.exe shortcut and enter the properties. From there you should replace the “Target” box in the Properties with the following:
“C:\Program Files\Java\jre6\bin\java.exe” -Xmx1024M -Xms512M -cp Minecraft.exe net.minecraft.LauncherFrame”
Additionally you may want to go into your control panel and uninstall the 32-bit standard version of Java.
Now that Java 64-bit is installed then you should see an increase performance in Minecraft! For more information on how to allocate more memory when running Java and Minecraft then see our tutorial.