Check the settings in eclipse.ini in your installtion (it will contain JVM settings). It's possible that they are configuring the JVM to make more efficient use of it than you are when you run the program.

http://wiki.eclipse.org/Eclipse.ini

http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html

Check the settings in eclipse.ini in your installation (it will contain JVM settings). It's possible that they are configuring the JVM to make more efficient use of it than you are when you run the program.

http://wiki.eclipse.org/Eclipse.ini

http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html