<form method="POST">
    <?php
    if (count($_POST) > 0) {
        echo '<pre>';
        print_r($_POST);
        die();
    }
    for ($i = 1; $i <= 1600; $i++) {
        echo "Field {$i} : <input type='text' name='field_{$i}' value='test {$i}'><br>";
    }
    ?>
    <input type="submit" value="Submit">
</form>