Etienne Kneuss has
posted about a new part of the Standard PHP Library that creates arrays that are up to thirty percent faster than normal methods - SplFastArray.
Antony got the idea to implement a C-like array wrapper in SPL: SplFastArray. The main advantage of that class is performance, it's indeed faster than PHP arrays. How so? No free lunch: The speedup comes from the fact that non-numeric indexes are not allowed and that the array is of fixed size.
The code sample shows the setting of the size for the array (and changing it) with a var_dump of the output result. This method is always faster than normal arrays, it just varies how much from system to system (anywhere from ten to thirty percent).
Etienne Kneuss' Blog: SplFastArray to speed up your PHP arrays - Read More... 
