Note: You are currently viewing documentation for Moodle 2.6. Up-to-date documentation for the latest stable version of Moodle may be available here: OPcache.
in Moodle 2.6!
The standard OPcache extension is strongly recommended; since Moodle 2.6, it is the only solution officially supported by PHP developers. The benefits are increased performance and significantly lower memory usage.
The OPcache extension is distributed as part of PHP 5.5.0 and later. It is available also for older stable PHP releases from PECL under the original name ZendOPcache.
NOTE: If you are running PHP 5.3 or 5.4 you can safely ignore the Environment Check message about OpCache. Nonetheless, it might be useful to upgrade Operating System/PHP and get to 5.5 or newer; as there have been all sorts of problems described on PHP 5.2 and 5.3, and upgrading PHP turned out to be the easier solution.
[opcache] opcache.enable = 1 opcache.memory_consumption = 128 opcache.max_accelerated_files = 4000 opcache.revalidate_freq = 60 ; Required for Moodle opcache.use_cwd = 1 opcache.validate_timestamps = 1 opcache.save_comments = 1 opcache.enable_file_override = 0 ; If something does not work in Moodle ;opcache.revalidate_path = 1 ; May fix problems with include paths ;opcache.mmap_base = 0x20000000 ; (Windows only) fix OPcache crashes with event id 487 ; Experimental for Moodle 2.6 and later ;opcache.fast_shutdown = 1 ;opcache.enable_cli = 1 ; Speeds up CLI cron ;opcache.load_comments = 0 ; May lower memory use, might not be compatible with add-ons and other apps.
When using non-Windows platforms, you have to use the zend_extension configuration to load the OPcache extension into PHP by adding to php.ini.
When using IIS you will need PHP 5.5 and you will need to add the extension for opcache under the ExtensionList section of the php.ini file. For PHP 5.3 and 5.4 you can download the binaries separately from  and you will also need to enter full absolute path to the module dll in php.ini.
[ExtensionList] ... zend_extension=php_opcache.dll