In an interview with Kotaku Rockstar have revealed that L.A. Noire is so big that it comes on 3 Xbox 360 game discs and one single-layer 25 GB blue-ray for the PlayStation 3.
"L.A. Noire was always going to be a massive game, from the size and detail of the world to the length of the cases, and of course, the sheer amount of MotionScan data required for the faces of over 400 actors in-game," Jeronimo Barrera told the site, "To tell the story and make the game we wanted to make, we knew that it was going to take an entire single layer Blu-ray disc and three Xbox discs."
A lot of the data, according to Barrera, is for the new MotionScan technology which allows almost real facial expressions on the characters and is significant when you come to solve crimes in-game.
To calm fears of crazy disc swapping requirements, Barrera confirms that disc swapping will occur only twice at natural breaks between cases without interrupting the flow of the game.