Sebastian Bergmann has a new post on his blog today with some PHP 5.1 Performance stats of the "execution models" (CALL, GOTO, SWITCH).

Over the last couple of days I benchmarked the three execution models (CALL, GOTO, SWITCH) that the new virtual machine of PHP 5.1 offers against PHP 5.0.4 and PHP 4.3.11 (results with GCC 3.4.4, GCC 4.0.1).

Initial results show that PHP 5.1's GOTO-based executor gives a 400% better performance than PHP 4 and PHP 5.0. The benchmark script used is available here.

It's pretty clear (especially from the graph) that PHP 5.1 gives a very large jump in performance - 400%, as mentioned above...