The "killer app" feature of CHD is that it uses lossless compression. Think of it like a ZIP file, but optimized specifically for disc images. It understands the difference between game code and empty padding.
Saturn emulators require BIOS files ( sega_101.bin , mpr-17933.bin , etc.). CHD files do not contain BIOS. Ensure your BIOS are in the correct system folder. RetroArch requires them in system/ folder. sega saturn roms chd
The standard tool is chdman , part of MAME. The process: The "killer app" feature of CHD is that