I have upgraded to the latest PivotX. Is it compatible with PHP 5.5? I've heard PHP 5.5 is great in the performance wise. It has its own opcode cache too. I am still unable to get it worked in PHP 5.5, gives 500 internal server error. Could you let me know what are the required PHP extensions to run PivotX? I am running a kind of a moderate to high traffic website with pivot. So performance really matters me to reduce the page load time. PHP 5.3, WinCache, IIS output caching and MySQL query cache does me fine right now. IIS output caching reduces the load time from 500 ms to even 10-20ms but the problem is when I enable it PivotX is not storing new comments (hash cash goes mad). I've been using PivotX for more than 3 years now. So these are the problems and things I've done so far.
Do you have any suggestions to increase performance in PivotX with or without PHP 5.5, MySQL tricks or anything else?

Thanks.