Ted Price: "Yes it is true - we are currently using more than 20 gigs. And yes, we do compress our level data. The fact that we store so much on disc is actually not that surprising when you look at the numbers. Consider that even with compression, each of our "levels" (or loaded areas) has more than 300 megs of unique data. And keep in mind that we're also streaming data during level playthroughs. It doesn't take too much level data before you've gone past what can be stored on a dual-layer DVD. And between single player and multiplayer we have a lot of level data (over 40 different large loaded areas) – yes, more than will fit on a dual layer DVD."