Using APC or OPcache with Magento

Magento is a resource‑intensive ecommerce platform, and enabling opcode caching is one of the most effective ways to improve performance. Both APC and OPcache store precompiled PHP code in memory, reducing the need for repeated compilation and speeding up page delivery.

About APC and OPcache

• APC (Alternative PHP Cache)

  • Works with PHP 5.4 and earlier.

  • Requires installation as a separate PHP extension.

  • May or may not already be installed on your server.

• OPcache

  • Built into PHP 5.5 and newer.

  • Drop‑in replacement for APC.

  • Enabled by default on most modern hosting environments.

Using APC or OPcache with Magento

1. Check PHP version

   • If running PHP ≤ 5.4, APC may be available.

   • If running PHP ≥ 5.5, OPcache is recommended.

2. Verify installation

   • Use phpinfo() or cPanel’s PHP Info to confirm APC/OPcache status.

   • Look for sections labeled APC or Zend OPcache.

3. No Magento configuration required

   • APC and OPcache operate at the web server level.

   • Magento automatically benefits from performance improvements once caching is enabled.

4. Optional tuning (OPcache)

   • Adjust settings in php.ini for optimal performance:

     opcache.enable=1
     opcache.memory_consumption=256
     opcache.interned_strings_buffer=12
     opcache.max_accelerated_files=65406
     opcache.revalidate_freq=2
     

   • These values can be customized depending on server resources.

Important Notes

• APC is deprecated; use OPcache if possible.

• Always clear Magento’s cache after enabling or changing opcode caching.

• For more details, see the official PHP OPcache documentation.