CHD uses lossless compression to shrink GDI files by 40–60% without losing any data quality.
When searching for Dreamcast ROMs, you will mostly choose between GDI and CDI formats. Understanding their differences determines the quality of your gaming experience. CDI (DiscJuggler Image) dreamcast roms gdi
6 Mar 2026 — CHD (recommended) For Sega Dreamcast, you should be using CHD files. Joey's Retro Handhelds CHD uses lossless compression to shrink GDI files
To make a CDI file, release groups downsampled high-quality audio, compressed video files, or stripped out content entirely. Therefore, for modern preservation, offering the game exactly as the developers intended. Why You Should Use GDI Roms release groups downsampled high-quality audio
