$limit = 200;
$offset = 0;
while (TRUE) {
    $posts = new WP_Query(array(
            'posts_per_page'        => $limit,
            'offset'                => $offset,
            'post_type'     =>  $post_type,
            'orderby'       =>  'title',
            'order'         =>  'ASC',
            'post_status' => array('publish', 'private', 'draft', 'inherit'),
    ));

    if (!$posts->have_posts()) break;

    while($posts->have_posts())
    {
            $posts->the_post();

            # do some echoing with the $post
    }

    $offset += $limit;
} /*(TRUE)*/

# do some echoing with the $post

# wipe post from memory
wp_cache_delete( $post->ID, 'posts' );
wp_cache_delete( $post->ID, 'post_meta' );

wp_cache_flush();