What are we looking at?
The chart above shows Ubuntu in a 2 and 8 core configuration (the x2 and x8), along with a Server 2008 instance.
What does it mean? The good folks over at FaceBook recently released a custom tool called HopHop that rewrites PHP into native C++ code. The upshot to this, as you can see, is bare-bones PHP code, that is, code which relies on math and loops and such, is much, much faster. Of course other code should be faster as well, though I have yet to benchmark more complex scripts.