I had a number crunching PHP batch program that was taking about 45 minutes to run. After a long and tedious rewrite in C++ the best I could get was about 5 minutes faster (~10% improvement). On line the main performance hit with PHP (relative to C++) is the interpretation which can largely be negated using APC for caching and optimizing the intermediate code. Considering the nature of on line programs I would expect even less that the 10% gain I squeezed from the batch program. Of course it's horses for courses but from my experience I find the 10:1 ratio unrealistic for real world applications..

I like it and I'm going to use it, thanks :-)