Note: You are currently viewing documentation for Moodle 3.9. Up-to-date documentation for the latest stable version of Moodle may be available here: admin/environment/custom check/php not 64 bits.

admin/environment/custom check/php not 64 bits

From MoodleDocs

This message means that your current PHP version is not 64 bits.

A new feature of PHP7 is it has now 64-bit version so it can use more than 4GB RAM and code performance can be potentially two times faster depending on the application design.