Support » Plugin: W3 Total Cache » Updated W3Cache and now very slow

  • Hi,

    The site in question is It was working fine, but I saw that W3 cache needed updating because of a security risk. I did this and now the site is very slow. 29s to load according to pingdom.

    Any ideas what to change to get the speed back? The settings that make w3cache work are:

    page cache – disk basic
    database – disc
    object – disc
    browser – enable
    cloudfare enable

    minify isn’t happy, but it wasn’t before.


Viewing 15 replies - 1 through 15 (of 22 total)
  • Yaa.. Latest version of this plugin Slow Down My Website.. Now i removed It! 🙁

    The latest version contains a critical Bug that came with the latest plugin security update.

    Cache files now get the string <?php /* appended on cache write, so that the files’ contents can’t be displayed by simply viewing them in the browser.

    The plugin’s authors simply fail to take the offset into consideration when reading cache files. This results in failed deserialization of the files’ contents and cache misses on every cache read.

    If you want to look into the issue, it is located in the File /wp-contents/plugins/w3-total-cache/lib/W3/Cache/File.php in Line 279. Note that the expire value is read from the first four bytes of the file. Since the update the first four bytes are just “<?ph”.

    You can either wait for a fix by the authors or fix it yourself by adding @fseek($fp, strlen("<?php /* ")); to Line 279 before $expires = @fread($fp, 4);.

    If you decide to add the mentioned changes, please note, that you do this at your own risk. I recommend switching from file/disc based caching engines to other available engines. Or wait until the issue is resolved.

    I have already notified the plugin’s author and still waiting for a response.

    Happened to me too.

    It started producing a lot of files too(+3gb very fast).

    Removed it.

    P.S: be careful after deleting. If you can’t see your images anymore change your permalink structure.

    Same here.
    If i had 2 websites on my vps i think i could crash the server rack lol. It only gives me problems when i log to the administration and ff i stay out of it the site is ok. When i need to post or do anything in the administration i deactivate the plugin (sometimes it isn’t an easy task).
    Waiting for a fix.

    Happened to me too, without any cache site loads in 1.2 seconds, with W3TC activated it loads in 5-10 seconds and cpanel tells me my site consumes up to 2 gb of ram memory …..

    My site went down from 29:th of december, coinciding with the new version of W3TC.. Waiting for a fix.

    It took me a long time to find the solution. It may seem obvious to some, but still I’ll post it for those waiting indefinitely for an update:


    kato, the plugin author retrofitted v0.9.2.5 changes into the older v0.9.2.4 archive, so anyone trying to downgrade won’t actually be downgrading–they’ll just be reinstalling v0.9.2.5 rebadged as v0.9.2.4

    Same thing happen to my site too…Its really slow now after updated to v0.9.2.5

    Same problems here:

    Seems the wp-includes/ files can’t be severd from my CDN, even if I have set them to be done so.

    Looking forward to the fix.

    Jumbo, then?

    kato, yes, it looks like the archive was left untouched, but that’s a pretty steep downgrade. I did a file comparison between the two and the differences are quite significant.

    I have several problems with the version of this plugin and performance of the admin section was one of them. However, when I disabled both database and object caches, this problem disappeared. Of course if you need to use these caches, this will not solve your problem. Might be worth to try though. is one of real alternative, for more problems, but for my personal opinion the best is old developmental release 2011-08-31 😉

    I had this ‘very slow loading’ problem as well using APC for caching Page, Minify, Database and Object – and Cloudflare CDN.

    Load times more than 6 secs reported by Pingdom.

    Fortunately I had an ‘old’ copy of v0.9.2.4 hanging around and have reverted.

    Everything is back as it was – website loading in under 2 seconds. Hopefully as the security bug seems to only affect database caching to disk, I’ll be OK.

    Same issue here… took me a while to figure this was it… what a frustrating day. 30 seconds or more for page load times.

    I’ve deactivated the plugin and the site is much better now. I know the plugin did help with the speeds on previous versions so hope the update fixes it.

Viewing 15 replies - 1 through 15 (of 22 total)
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