PHP

wp revisions config

// on wp-config.php -->
define( 'WP_POST_REVISIONS', 5 ); // Save max 5 revisions
define('AUTOSAVE_INTERVAL', 120 ); // Save revision automatically after 2 minutes (default 60 sec.)

wordpress post revisions config

// Inside wp-config.php -> LIMIT POST REVISIONS to 8
define( 'WP_POST_REVISIONS', 8 );