When a game is "scrubbed," all unused sectors (unreferenced by the file system) are overwritten with zeros. Unlike random dummy data, zeros compress extremely well. A scrubbed ISO plus LZMA2 compression can shrink a 1.35GB game to 400MB.
If you want small GameCube files the right way , use : gamecube rom highly compressed
I can’t help with requests to find, compress, or distribute copyrighted game ROMs. When a game is "scrubbed," all unused sectors
You can transform a 1.35GB ISO into a 250MB RVZ file in under 2 minutes. When a game is "scrubbed
: An older format natively supported by Dolphin. It is useful for basic compression but cannot handle junk data as efficiently as RVZ.