MemoryStresser.php

<?php

/**
 * WARNING: Keep your machine safe! This is just for testing purpose.
 *
 * ini_set("memory_limit", -1); or you can set it manually in php.ini
 */

declare(strict_types=1);

echo "[*] Can your machine handle this script?" . PHP_EOL;

while (true) {
    $stacks = [];

    for ($i=0; $i < 3; $i++) {
        $stacks[] = range(1, 1024 * 1024 * 10);
    }

    unset($stacks);

    echo "[!] Updating memory..." . PHP_EOL;
}