Hi @lonabsarti,
Whilst we are constantly working on making the plugin faster, perform better, and use less resources, there are not set amounts of RAM, CPU or database queries that we know Wordfence will definitely require in each use-case or hosting environment. The cases of slow-down are small in relation to the quantity of customers using Wordfence, but does crop up from time to time with certain configurations or larger databases/number of installed plugins.
The amount of RAM used on a WordPress site is generally impacted by all plugins installed on the site. If possible, please remove any plugins that are not necessary, or consider increasing the memory available to the site.
If your client is in an environment with limited resources, you could have them enable Use low resource scanning in Wordfence > Scan > Scan Options and Scheduling > Performance Options. This will cause scans to use less resources but take longer to complete. You can read more about the performance settings at https://www.wordfence.com/help/scan/options/#performance-options
You could also set max_execution_time = 60 in php.ini, Wordfence’s scan only ever attempts to use half of this value by default.
Your WP_MEMORY_LIMIT should be set to 128M or 256M in wp-config.php. WooCommerce, for example, recommends 64M minimum, so if you also have many hits on the site at once especially during a Wordfence scan, a lower limit here could be reached fairly easily. Your PHP memory_limit value should be set to the same or higher to accommodate this change otherwise there won’t be enough room for WordPress to use the higher value it is requesting.
I hope this helps!
Margaret
