http://www.lornajane.net/posts/2013/php-version-adoption
But what is even more interesting is the benchmarks of each PHP version which I'm going to reproduce here:
- 5.2.17: 3.77 seconds
- 5.3.23: 2.63 seconds
- 5.4.15: 1.98 seconds
- 5.5RC1: 2.11 seconds
Assuming that benchmark accurately reflects your own application, then your code on php 5.4 will run in 75% of the time it previously took on 5.3. (PHP 5.5 appears to only be 80% of php 5.3 speed; not sure if the slowdown was due to working with a release candidate, rather than the final release?)
(PHP 5.5 stops supporting Windows XP and Windows 2003, and adds nothing that caught my interest. PHP 5.4 on the other hand had some interesting features, and now I see a worthwhile speed-up I will target that for new projects.)
