If you are playing on a PC using the RPCS3 emulator, the game needs to be in a folder format (JB Folder) or a standard .ISO . Open . Click File > Add Games .

Are you playing on a or the RPCS3 PC emulator ? What specific game are you trying to compress?

Switching to highly compressed formats offers several distinct advantages for modern retro gamers:

You can fit three to four times as many games onto your external hard drive or PC storage.

Some of the most popular PS3 ISO highly compressed new games include:

Copy the .iso file to your PS3 internal hard drive ( ) or an external USB drive (formatted to NTFS or exFAT). Where to Find "New" Highly Compressed ISOs

: Highly compressed, clean ISOs often load faster on PC emulators like RPCS3. How to Compress PS3 Games Using Modern Tools

Forums dedicated to PS3 homebrew often have dedicated sections for compressed ISOs.

Steer clear of files claiming to be compressed into proprietary, obsolete formats like .ecm or .cso (which is meant for PSP, not PS3). These often corrupt the data.

Here is everything you need to know about the newest compression methods, how to unpack them, and how to play them flawlessly on modern emulators or original hardware. Understanding PS3 ISO Compression

The old standard was LZMA2. The "new" standard is with Zstandard (zstd). It compresses PS3 data structures faster and smaller.