When downloading highly compressed PS3 games, make sure to take the following safety precautions:

The demand for isn't just about saving space; it's about preservation. As Blu-ray discs rot and digital storefronts close, compressed ISOs ensure that masterpieces like Metal Gear Solid 4 and Resistance 3 remain playable forever.

: Excellent for official digital releases (PKG format) which can be installed directly from the PS3's XMB menu. Myrient (via FTP)

So you have downloaded a file named God_of_War_3_HC.7z (4GB) that should extract to a 35GB ISO. Here is the workflow:

The PlayStation 3 is a paradox. It is the “un-emulatable” beast, the console with the cell processor that makes developers cry and engineers smile. Yet, more than a decade after the release of the PS4, the thirst for PS3 games hasn’t died. It has mutated.

To understand why "highly compressed" PS3 games are mostly a myth, one must look at the file structure of the media itself.