Maximum Java heap size of a 32-bit JVM on a 64-bit OS

Question

The question is not about the maximum heap size on a 32-bit OS, given that 32-bit OSes have a maximum addressable memory size of 4GB, and that the JVM\'s max heap size depen

Answer 1

The JROCKIT JVM currently owned by Oracle supports non-contiguous heap usage, thus allowing the 32 bit JVM to access more then 3.8 GB of memory when the JVM is running on a 64 bit windows OS. (2.8 GB when running on a 32 bit OS).

http://blogs.oracle.com/jrockit/entry/how_to_get_almost_3_gb_heap_on_windows

The JVM can be freely downloaded (registration required) at

http://www.oracle.com/technetwork/middleware/jrockit/downloads/index.html