In CentOS 7, CPU information is stored in /proc/cpuinfo, so you can implement to acquire CPU information in the system.

<?php

// programmed by Chun Kang (2021-01-06)

function check_cpu()
{
        $cpu_info = file_get_contents( "/proc/cpuinfo");
        if (preg_match("/AMD/", $cpu_info))
        {
                return "AMD";
        }
        else if (preg_match("/Intel/", $cpu_info))
        {
                return "Intel";
        }

}

$cpu = check_cpu();

echo "CPU = {$cpu}\n";

?>