php performance on IIS 6

I was having a performance problem when running any php pages on IIS 6, the problem was that the page would load in the browser extremely slow, running a simple loop would take ages to output anything. I didn't get into testing much to find out where the speed issues are exactly but I found a fix for the problem. Also to note was there was no noticeable load on the server (cpu or memory) while processing. After googling around a bit and seeing a number of people with similar problems I started going through the php.ini file to see what could be causing the performance problem. What I found was simply setting output-buffering to "on" in the php.ini dramatically increased the speed. (Don't ask me why) I now have php operating fine on IIS6