OPcache can only be compiled as a shared extension. If you have disabled the building of default extensions with --disable-all, you must compile PHP with the --enable-opcache option for OPcache to be available.
Once compiled, you can use the
zend_extension configuration
directive to load the OPcache extension into PHP. This can be done with
zend_extension=/full/path/to/opcache.so on non-Windows
platforms, and zend_extension=C:\path\to\php_opcache.dll
on Windows.
Note:
If you want to use OPcache with » Xdebug, you must load OPcache before Xdebug.
The following settings are generally recommended as providing good performance:
opcache.memory_consumption=128 opcache.interned_strings_buffer=8 opcache.max_accelerated_files=4000 opcache.revalidate_freq=60 opcache.fast_shutdown=1 ; prior to PHP 7.2.0 opcache.enable_cli=1
You may also want to consider disabling opcache.save_comments and enabling opcache.enable_file_override, however note that you will have to test your code before using these in production as they are known to break some frameworks and applications, particularly in cases where documentation comment annotations are used.
On Windows, opcache.file_cache_fallback should be enabled, and opcache.file_cache should be set to an already existing and writable directory.
A full list of configuration directives supported by OPcache is also available.
While the "suggested" opcache settings for php.ini might be appropriate for a production server, you're going to want to change several while you're developing, or you're not going to see any changes to your code. Get familiar with what they mean before blindly pasting that into php.ini and assuming things are going to work well.