CHD (Compressed Hunks of Data) is a lossless compression format originally created for MAME (arcade emulation). It compresses disc-based games (CD, DVD, GD-ROM) without removing any data.
chdman createcd -i "game.cue" -o "game.chd" Windows (PowerShell): ps2 chd roms
For PS2 games, CHD files are typically than ISO or BIN/CUE, while remaining byte-for-byte identical to the original disc when decompressed. ✅ No quality loss – same CRC/SHA1 as the original ISO. 2. Why use CHD for PS2 instead of ISO? | Feature | ISO / BIN+CUE | CHD | |--------|--------------|-----| | Compression | None (or ZIP/RAR, not usable directly) | Lossless, chunk-based | | File size | ~4.7 GB (DVD5) or ~8.5 GB (DVD9) | ~2–4 GB | | Multiple files per game | Often yes (e.g., .bin+.cue) | No – single file | | Streaming performance | Standard | Excellent (seek table optimized) | | Emulator support | All | PCSX2, AetherSX2, RetroArch, XEMU | CHD (Compressed Hunks of Data) is a lossless
Get-ChildItem -Filter *.iso | ForEach-Object chdman createcd -i $_.FullName -o "$($_.BaseName).chd" ✅ No quality loss – same CRC/SHA1 as the original ISO