Here are some ways you can optimise the performance of PHP
Use Latest Version¶
Performance improvements have been a major theme of PHP updates of late. It should be the first thing you do when looking to improve performance
Opcode caching should be enabled which can provide a significant performance boost
There are many opcache settings which can be configured when tuning for performance: http://php.net/manual/en/opcache.configuration.php
Opcode Cache Files¶
A further tweak to this is to have the opcode cache store to files.
An extension such as this one can then be used to "warm up" the opcode cache files for maximimum benefit: https://github.com/jderusse/composer-warmup/blob/master/Readme.md