When playing disc-based games on PS4, do I need to install data to the hard drive?
Yes, all PS4 Blu-ray Disc games must be cached to the hard drive to ensure a smooth gaming experience. However, certain titles may not require you to wait for the game data to be fully cached before starting gameplay. In order to start playing disc-based games, users will need to insert the game disc into PS4 just like on the PS3 system.
To je s nedavnog FAQ-a.
Način pisanja, pogotovo "cached" izraz, nekako govori da to neće biti nekakve potpune instalacije, tj. da će BluRay disk i dalje biti potreban. Evo, primjerice na Wii U svaka retail igra zauzima i ponešto mjesta na sistemskoj memoriji - oko 50-200 MB recimo, dio memorije se mora rezervirati za igru, naravno - ali to nije "obvezna instalacija".