MGS4 is "just" 30GB
there are padding sectors for making the game load faster so while the disc is 46.6 GB the actual the game data is 29.9GB (MGS4 = 27.2GB, MGO = 2.7GB).
http://pocketnews.cocolog-nifty.com/pkns/2008/06/metal_gear_soli_9cba.html
Face the future.. Gamecenter ID: nikkom_nl (oh no he didn't!!)