Dreamcast+games+highly+compressed+better

Here is why experienced emulator users (using Flycast, Redream, or RetroArch) hunt for highly compressed sets:

If you are not planning to play the games immediately—only archive them on a cold storage drive—you can go smaller than CHD.

The 7z Method:

The RVZ Method (Dolphin trick): The GameCube/Wii emulator Dolphin uses RVZ, which is superior to CHD for GC games. However, do not use RVZ for Dreamcast. Flycast does not support it. Stick to CHD.

Dolphin (GameCube/Wii) popularized RVZ compression. The Dreamcast community has adapted similar principles. Modern converters can take a full 1.3GB GDI of Skies of Arcadia and crush it to a 450MB CHD. That is "better" because it allows you to store three times as many games on your Steam Deck or phone's SD card. dreamcast+games+highly+compressed+better

Be careful with extreme compression found on the internet. If you download a Marvel vs. Capcom 2 file that is only 50MB, it is highly likely that:

Recommendation: Aim for the "sweet spot." A library of CHD files will give you roughly 40-50% storage savings with 100% game integrity. That is "better" compression—efficient, stable, and safe. Here is why experienced emulator users (using Flycast,

For most users:

“Better” does not mean smallest. It means the smallest possible without breaking the game’s soul. The RVZ Method (Dolphin trick): The GameCube/Wii emulator

To get better performance, compatibility, or quality while still saving space:

| Goal | Recommended Approach | Compression Ratio | Quality | |------|----------------------|-------------------|---------| | Best for real hardware (burn CD-R) | Use optimized CDI from trusted groups (ReviveDC, DCCM). Avoid “ultra” compressed versions. | ~30–40% size reduction | Good | | Best for emulation (storage saving) | Convert GDI to CHD (lossless). No quality loss. | ~40–60% of original | Perfect | | Best for low storage (e.g., retro handhelds) | Use lossy CDI with mild audio downsampling (44.1→22kHz stereo) + intact video. | ~25–35% of original | Acceptable | | Avoid entirely | “100MB rips” with stripped music, mono audio, no FMV. | Extreme | Poor |