Title: High CPU usage when swtiching theme Last modified: February 13, 2018 --- # High CPU usage when swtiching theme * Resolved [kaoruc](https://wordpress.org/support/users/kaoruc/) * (@kaoruc) * [8 years, 2 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/) * My whole site was crashed and the hosting is blocked because of the CPU high usuage. “POST /wp-admin/admin-ajax.php?action=wp_1_wc_regenerate_images&nonce =cc4eaf3f08 HTTP/1.0” 200 – * I was warned that if it happens again, I will be peremently put on limit. Is there a option or setting on the plugin to stop that from happening? I seriously thing this update should be fix ASAP Viewing 7 replies - 1 through 7 (of 7 total) * Plugin Contributor [Mike Jolley](https://wordpress.org/support/users/mikejolley/) * (@mikejolley) * [8 years, 2 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/#post-9972970) * Is this on multisite or anything specific? How many product images do you have? * It can be disabled via a filter, and 3.3.2 will have a link to cancel the resize process, but I wonder why it would be a problem for your host vs any other regen plugin such as [https://en-gb.wordpress.org/plugins/regenerate-thumbnails/](https://en-gb.wordpress.org/plugins/regenerate-thumbnails/)– they all work in a similar fashion. * [viper007bond](https://wordpress.org/support/users/viper007bond/) * (@viper007bond) * [8 years, 2 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/#post-9973023) * Stuff like this usually happens on cheap, crappy hosts. I can’t speak as to whether this is the case in this situation or not (I don’t know who your host is), but it’s suspicious that a host is issuing a warning for using the CPU for a while in order to generate some new thumbnail images. That’s not that unusual of a thing to be doing. * Personally I’d install [Jetpack](https://jetpack.com/) and enable [the Image CDN functionality](https://jetpack.com/support/photon/). This will offload image serving and more importantly thumbnail generation to the WordPress.com servers. - This reply was modified 8 years, 2 months ago by [viper007bond](https://wordpress.org/support/users/viper007bond/). * Thread Starter [kaoruc](https://wordpress.org/support/users/kaoruc/) * (@kaoruc) * [8 years, 2 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/#post-9980149) * My website is not a multisite, nothing especially unique but just a regular website I would like to use for event registration. * I’m using the Siteground hosting plans, and have tried on both the StartUp and GrowBig plans. Have installed the Jackpack and activated their image feature as well. When I switch theme with the Woocemmerce plugin, it keeps generate the POST /wp-admin/admin-ajax.php?action=wp_1_wc_regenerate_images and boost the CPU to a very high usage. The Siteground warned me if I generate than high volume again, I will be blocked. * I never use [https://en-gb.wordpress.org/plugins/regenerate-thumbnails/](https://en-gb.wordpress.org/plugins/regenerate-thumbnails/) and don’t have similar plugin on my site. * Plugin Contributor [Mike Jolley](https://wordpress.org/support/users/mikejolley/) * (@mikejolley) * [8 years, 2 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/#post-9981033) * Resizing images is CPU intensive. This happens whenever you upload an image to WP (usually) so I’m unsure why the host would mind unless it’s a shared host ( which may not be ideal for eCommerce anyway). * In 3.3.2 we’ve changed our code to disable background processing when Jetpack Photon is present, since it’s not needed. This should be out next week, however, we’ve pushed out a pre-release version to .org (3.3.2-rc.1) so if you’d like to help test that you can do so using a plugin like “WP Rollback” to switch to that version before it’s released officially. * Thread Starter [kaoruc](https://wordpress.org/support/users/kaoruc/) * (@kaoruc) * [8 years, 2 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/#post-9996824) * Yes, I’m using a shared hosting, but there is no traffic on my account because it’s a testing site for my development. However, I don’t want to risk my productive site on this plugin. * The high CPU usage is caused when I tried to switch theme, so I guess the system was trying to regenerate the thumbnails all at once, and this is what make the hosting initial an alert. Resizing one individual image might be not as intensive as when all images are regenerating. In addition, I don’t think it is a favorable behavior as well. There is no reason to resize the thumbnail or existing image because a user switch theme. * [Thomas Shellberg](https://wordpress.org/support/users/shellbeezy/) * (@shellbeezy) * Automattic Happiness Engineer * [7 years, 11 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/#post-10365467) * [@kaoruc](https://wordpress.org/support/users/kaoruc/) Have you retested this with the newest version of WooCommerce? * [jessepearson](https://wordpress.org/support/users/jessepearson/) * (@jessepearson) * Automattic Happiness Engineer * [7 years, 11 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/#post-10392883) * We haven’t heard back from you in a while, so I’m going to mark this as resolved– if you have any further questions, you can start a new thread. Viewing 7 replies - 1 through 7 (of 7 total) The topic ‘High CPU usage when swtiching theme’ is closed to new replies. * ![](https://ps.w.org/woocommerce/assets/icon.svg?rev=3234504) * [WooCommerce](https://wordpress.org/plugins/woocommerce/) * [Frequently Asked Questions](https://wordpress.org/plugins/woocommerce/#faq) * [Support Threads](https://wordpress.org/support/plugin/woocommerce/) * [Active Topics](https://wordpress.org/support/plugin/woocommerce/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/woocommerce/unresolved/) * [Reviews](https://wordpress.org/support/plugin/woocommerce/reviews/) * 7 replies * 5 participants * Last reply from: [jessepearson](https://wordpress.org/support/users/jessepearson/) * Last activity: [7 years, 11 months ago](https://wordpress.org/support/topic/high-cpu-usage-when-swtiching-theme/#post-10392883) * Status: resolved