Increase memory and execution time for WP admins and crons.

my_init_memory.php

<?php
/**
 * Increase memory and execution time for WP admins and crons
 * Add this code into a custom plugin or code snippet.
 */
function my_init_memory() {
	if( current_user_can( 'manage_options' ) ) {
		ini_set( 'max_execution_time', 300 ); //300 seconds = 5 minutes
		ini_set( 'memory_limit', '812M' );
	} elseif ( wp_doing_cron() ) {
		ini_set( 'max_execution_time', 300 ); //300 seconds = 5 minutes
		ini_set( 'memory_limit', '300M' );
	}
}
add_action( 'init', 'my_init_memory', 1 );