Blu-ray discs can hold a ton of information, with single layer discs at 25GB and dual layer at 50GB. Blu-ray XL discs can hold even more information (100GB for triple layer and 128GB for quadruple), but Square Enix's new Luminous game engine may provide some troubles. Speaking to RPGsite, Square Enix Chief Technical Yoshihisa Hashimoto and producer/director of the Luminous demo does not think a Blu-ray disc will hold all the information for its new games. The engine pulls down all the data in real-time, which has gameplay that looks on par with CG cutscenes, but Hashimoto says the data is too massive to be used in a game. The data can be compressed down small enough to fit, but Square Enix did not have the time before showing E3 demo.
Hashimoto thinks the compression will not alter the look or feel of the game, but even with the compression it may not all fit onto one Blu-ray. Whether that means a dual layer disc at 50GB or a quadruple layer BD-XL disc at 128GB is unknown, but either way, the amount of data would be staggering.