Last Modified: 10.10.2012
Web servers waste up to 60% of time for repetitive pre-recompilation of PHP code for execution.
A key method that would allow to reduce the processor load is using a PHP pre-compiler.
Today, the following PHP pre-compilers are available on the market:
Alternative PHP Cache (APC)
Zend Performance Suite
Currently, APC (Alternative PHP Cache) is the most popular and developing product. We expect to see it included in the PHP6 package. We recommend APC, or eAccelerator as a quality and proved alternative. Remember to reserve sufficient memory for compiled PHP scripts. 16 to 24 MB is usually enough, but you can increase it to 32 MB on the safe side, to account for Control Panel scripts. The memory is shared between the web server processes which means that it will be reserved only once.
To reduce memory eaten by the web server processes, remove all the unused PHP modules at the compilation or run time.
To boost the PHP session performance, switch from file based sessions to shared memory sessions. Compile PHP with the --with-mm option and set the session.save_handler=mm parameter in php.ini.
This option is not available for Windows platforms.