Portal 2 – Overclocker Achievement Guide Posted on April 30, 2011 by erma Geoff and Jack haul butt to grab the "Overclocker" achievement in Portal 2. Get your running shoes on. To view this animated banner you need to have Flash Player 9 or newer installed and JavaScript enabled. BannerSnack is a professional, easy to use Flash & GIF creator application. Share this:FacebookTwitterTumblr