Eclipse updating indexes java heap space
As of Java SE 6, the Windows /3GB feature is not supported. Pooling objects will cause them to live longer than necessary.
If your application requires a very large heap you should use a 64-bit VM on a version of the operating system that supports 64-bit applications. The garbage collection methods will be much more efficient if you let it do the memory management. Don't call System.gc(), Hot Spot will make the determination of when its appropriate and will generally do a much better job.
This FAQ answers common questions about Java Hot Spot Technology and about performance in general.
Unless otherwise noted, all information on this page applies to both the Hot Spot Client VM and the Hot Spot Server VM as of Java SE version 1.4. Are there any resources for troubleshooting Hot Spot issues?
On most modern 32-bit Windows systems the maximum heap size will range from 1.4G to 1.6G.The only thing that you can do is to set the number of file descriptors allowed on the system higher.