All wii full wii iso are dvd-5, with a few dvd-9, but the games are always smaller. The rest of the disk has updates and junk data. When you copy a game to a thumb drive, or hd, only the game partition is copied by default, this effectively shrinks the iso. All games vary in size depending on the complexity of the graphics. The NSMB 350mb is a good example, most game are between 1-2g, some are close to 4g, it depends. You can use wbfs manager to format your media and copy your games removing this junk data in the process. Hope this helps.