When archiving a game like Wii Sports (approx. 0.4 GB of actual data) in a raw ISO format, the file size remains 4.7 GB to maintain the disc geometry. This results in a significant waste of storage space—often a ratio of 10:1 or higher—for archives housing hundreds of titles.
Users on platforms like generally report that Wii WBFS (Wii Backup File System) Wii Wbfs Rom Archive