Why is the 64bit JVM faster than the 32bit one?

Question

Recently I\'ve been doing some benchmarking of the write performance of my company\'s database product, and I\'ve found that simply switching to a 64bit JVM gives a consiste

Answer 1

The 64-bit instruction set has 8 more registers, this should make the code faster overall.

But, since processsors nowaday mostly wait for memory or disk, i suppose that either the memory subsystem or the disk i/o might be more efficient in 64-bit mode.