If you are archiving games to save space on a backup drive, use the .7z format, set the compression level to "Ultra," and use the "LZMA2" method.
Practical tips for managing compressed PS3 games Ps3 Game Highly Compressed
A single .iso file. This is the preferred format for modern PS3 homebrew as it offers better compatibility and faster loading times. If you are archiving games to save space
Games with massive assets are the most common targets for high compression: God of War III : Known for its massive scale and high-resolution textures. Metal Gear Solid 4 Games with massive assets are the most common
In simple terms, a "highly compressed" PS3 game is a standard game file that has been significantly reduced in size, often far beyond what a typical compression tool like WinRAR or 7-Zip can achieve. Standard Blu-ray discs can hold up to 50GB of data, but these compressed versions can sometimes be shrunk by 50% to 90% or more.
When looking for files, you will generally encounter these formats: