By default, Eclipse allocates a maximum of 256MB of Java heap memory, which is usually enough for most development tasks. However, depending on the JRE that you are running and if you are working with many additional plug-ins and have many files open, you may need to increase your amount of memory. Use the -vmargs command line argument to increase your heap memory, with the set to a value greater than "256M":

eclipse -vmargs -Xmx

If you are using a Sun VM, you may also need to increase the size of the permanent generation memory, which has a default maximum of 64MB. Use the -XX:MaxPermSize=[memory size] argument to increase the maximum permanent generation size:

eclipse -vmargs -XX:MaxPermSize=

Note: Check your VM documentation to see if this argument is available for your VM.

Note:

Setting memory sizes to be larger than the amount of available physical memory on your machine will cause can cause issues with Java, which will severely degrade your performance.

You can also add this entry to your aptana.ini or eclipse.ini file (found in the top level of your installation folder).

For standalone Aptana Studio:

    -name
    Aptana
    -vmargs
    -Xms512m
    -Xmx512m
    -XX:PermSize=256m
    -XX:MaxPermSize=256m
    -Djava.awt.headless=true

For Eclipse:

    -showsplash
    org.eclipse.platform
    -vmargs
    -Xms512m
    -Xmx512m
    -XX:PermSize=256m
    -XX:MaxPermSize=256m

If you are on OS X, your .ini file is located in a slightly different spot:

1. Navigate to the Applications folder. Open the Aptana Studio folder.
2. Right-click (or control-click) on the Aptana Studio application. Choose "Show package contents".
3. Navigate to Contents/MacOS/AptanaStudio.ini.
4. Edit AptanaStudio.ini, the same was as above in the standalone version.
5. Save the file.
6. Close any folders you just opened.

You can follow the same procedures on Eclipse. The folder structure will be identical, and look for the eclipse.ini file