IIS 7 and Above
FastCGI / CGI - php-cgi.exe - Memory usage
Re: FastCGI / CGI - php-cgi.exe - Memory usage
Dec 31, 2018 04:33 PM|lextm|LINK
The process php-cgi.exe is the one who executes your PHP code. So its memory usage is fully controlled by the PHP application. Whether 600MB is reasonable can only be answered by the original developers/vendors.
BTW, PHP 5.6 support just expired, http://php.net/supported-versions.php so ideally you should upgrade to 7.2 or 7.3 and test again.