Form php

for such big files use ftp, you can use a php ftp class. never change those values in such extreme.
here you can get a free php ftp uploader http://bdhacker.wordpress.com/…-php-ftp-uploader-script/

Quote from theprincy

I'm doing a php form to upload files over 500mb but unfortunately not the form itself does not load files larger than a few mb.
I changed upload_max_filesize, post_max_size, max_execution_time, memory_limit is the domain that the general one, by any chance there is any other block on the server? I'm going crazy

Hello ;

Yes, modification of PHP parameter is not sufficient... What i-MSCP server implementation you are using? ITK? FCGI? PHP-FPM???

So you must also review the parameters from the /etc/apache2/mods-available/fcgid_imscp.conf. They are well commented.