Most of the information in this section about altering the memory model and running out of native heap is relevant only to the 32-bit model, because the 64-bit model does not suffer from the same kind of memory constraints.
The 64-bit JVM can suffer from memory leaks in the native heap, and the same methods can be used to identify and pinpoint those leaks. The information regarding the Java™ heap relates to both 32- and 64-bit JVMs.