A standard .iso file is a raw sector-by-sector copy of a data disc (CD, DVD, or Blu-ray). When you rip a PC game or a movie DVD, you get a standard ISO. Operating systems mount these ISOs using a standard filesystem (UDF or ISO9660).
A valid XISO file is usually much smaller than a redump ISO. If your game is still huge, it wasn't converted properly. xemu convert iso to xiso
For most users, extract-xiso is the most reliable and straightforward method. Here’s how to use it step-by-step: A standard
How to Convert ISO to XISO for xemu: A Complete Guide The xemu emulator is the gold standard for playing original Xbox games on modern hardware. However, if you dump your retail Xbox discs, you will likely end up with standard ISO files. Standard ISOs contain a "Video" partition meant for DVD players, leaving the actual game data hidden in an unreadable format. A valid XISO file is usually much smaller than a redump ISO
XISO files remove the junk data, making the game file much smaller (sometimes reducing a 7GB game down to 1GB or less).