thanks for the slides -- there's quite some stuff i didn't know of in php 5.3. i'm interested in this garbage collector stuff -- the documentation doesn't provide any additional useful information on this. could you please explain, what this is for and when to use / not to use?
In most cases you do not need to use a garbage collector. However if your application or framework your application uses ends up utilizing large amount of memory. It is very likely that memory is actually marked as free within the script, but in normal flow will not physically be freed until the end of the request. Using the garbage collector will allow you to force PHP to physically free the no-longer used memory, before the request is finished.
Regarding the note about PHP 5.3 performance on Windows:
"Substantial performance improvements in Windows (40% +)"
I know that there is a lot of work went into PHP 5.3 to improve its performance, compatibiity and stability on Windows and its great to see that it is now much faster.
I am interested to find out what critera is used when measuring the performance of PHP from version to version. Are there some benchmarking tests that are used to determine the performance improvements like the one mentioned in your slides?