Title: [Plugin: W3 Total Cache] Xcache clarification
Last modified: August 19, 2016

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# [Plugin: W3 Total Cache] Xcache clarification

 *  [Joost Schuur](https://wordpress.org/support/users/jschuur/)
 * (@jschuur)
 * [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-xcache-clarification/)
 * This is more of a question to clarify my own curiosity than a support one.
 * If Xcache is an opcode caching mechanism, how does this help serve static content
   out of memory? If I keep my page cache set to ‘Opcode: Xcache’, am I in fact 
   still dynamically generating pages every time, simply with the benefit of the
   opcode being pre-cached already? Or is there some other feature of Xcache that
   you’re taking advantage of, where it does memcache-like caching of the output
   of whole URLs e.g.?
 * I was intrigued by your [recent comment](http://wordpress.org/support/topic/plugin-w3-total-cache-xcache-support?replies=13#post-1638840)
   that single server sites might want to try advanced file based caching after 
   all.
 * I’m running W3 Total Cache on nginx with Xcache set for a 128 meg cache size 
   for a small blog right now. At 64 megs, the Xcache admin panel would still show
   the PHP cache max out after less than half an hour.
 * [http://wordpress.org/extend/plugins/w3-total-cache/](http://wordpress.org/extend/plugins/w3-total-cache/)

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Plugin Contributor [Frederick Townes](https://wordpress.org/support/users/fredericktownes/)
 * (@fredericktownes)
 * [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-xcache-clarification/#post-1624140)
 * Opcode caches require PHP to be invoked to cache compiled scripts and access 
   stored objects. When you enable opcode as the storage engine for page caching,
   the entire uncompressed and gzip compressed versions of a given page are stored
   in the opcode cache and returned if they have not expired.
 * Different web servers have different levels of peak performance when working 
   with PHP. Nginx or Litespeed are typically much faster than Apache for example
   when running PHP. Mileage varies, but your web server is (by default) optimized
   for reading from disk rather than memory and use of memory caching is geared 
   towards alleviating specific bottlenecks, typically related to execution time
   for PHP rather than total response time for static objects.
 *  Thread Starter [Joost Schuur](https://wordpress.org/support/users/jschuur/)
 * (@jschuur)
 * [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-xcache-clarification/#post-1624197)
 * So in a nutshell, while Xcache can not only cache compiled script opcode, but
   also the output, thus bypassing even executing the opcode, there is a slight 
   overhead in invoking PHP?
 * Sounds like I’ll give advanced disk based cache a try then for my site.
 *  Plugin Contributor [Frederick Townes](https://wordpress.org/support/users/fredericktownes/)
 * (@fredericktownes)
 * [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-xcache-clarification/#post-1624272)
 * You can’t bypass exucuting opcode, that’s what happens when you have it installed
   and PHP is invoked. Instead of creating a page, if that file already exists in
   opcode (memory), it is returned instead of executing compiled scripts. Invoking
   PHP is slower than just returning a file from disk (in general). Nginx is not
   officially supported with latest functionality now.

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘[Plugin: W3 Total Cache] Xcache clarification’ is closed to new replies.

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 * 3 replies
 * 2 participants
 * Last reply from: [Frederick Townes](https://wordpress.org/support/users/fredericktownes/)
 * Last activity: [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-xcache-clarification/#post-1624272)
 * Status: not a support question