Ubuntu 11.04: i686 vs. i686 PAE vs. x86_64

PHP was also quicker to build on the 64-bit system.

The Bullet Physics Engine performance improved slightly with the PAE kernel but there was a significant boost in performance when going from 32-bit to 64-bit. The Core 2 Duo and Core i7 notebooks were both 20% faster with the 3000 Fall Bullet test.

Bullet's 1000 Stack test was also about 20% faster when going from i686 to x86_64.