Sebastian Bergmann has posted the results of some benchmarking on the compilation he's done on the branches of PHP from version 3.0 all the way up to 5.3-CVS.
As people keep asking me for an update to my previous benchmarks (PHP / GCC / ICC Benchmark, PHP 5.1 / GCC Benchmark (Update), and PHP 5.1 Performance, I quickly ran a new benchmark today.
He rendered the results out into a series of charts defining the number of total seconds taken for the compile and how long each of the components took. It's impressive to see how much of a jump there was between the 3.0 series and 4.3.
He also includes his compile settings (and machine information) as well as the numbers for the results if you'd like to graph them out yourself.