PHP and Recursion

Hi guys, I am working on script that will assemble data to create a page and have come to an interesting conclusion. Its a perfect fit for recursion as part 1 of the doc will require additional parts and so on. I wrote it at first with two loops. The first loop gathered data and the second arranged the data. For completeness sake, I rewrote it using recursion where I have a get_data() function that is called within itself if said data needs more data. The results were quite suprising. I get about a 80% increase in speed (using openload with 20 concurrents to test) using the recursion. Now, at most, I will be recursing 4 or 5 levels deep. Does PHP optimize recursion in such a way that this is expected or did I get lucky and I may hit a wall when I am not looking?