Now go reclaim your disc images. Q: Can I convert CHD to ISO without losing quality? A: Yes. CHD is lossless. Converting back to ISO restores the original 1:1 binary copy.
Use chdman verify : chdman verify -i input.chd convert chd to iso better
if exist "!OUTPUT_ISO!" ( echo Skipping !BASENAME! - ISO already exists >> %LOG_FILE% ) else ( echo Converting !BASENAME!.chd ... >> %LOG_FILE% %CHDMAN% extracthd -i "%%f" -o "!OUTPUT_ISO!" -f if !errorlevel! equ 0 ( echo Success: !BASENAME! >> %LOG_FILE% ) else ( echo FAILED: !BASENAME! - Check CHD integrity >> %LOG_FILE% ) ) ) echo Finished at %time% >> %LOG_FILE% echo ----------------------------------- >> %LOG_FILE% pause Now go reclaim your disc images
A: The multi-threaded PowerShell script above. On an NVMe SSD with 8 threads, you can convert a 700MB game in ~12 seconds. CHD is lossless
Before converting, generate a SHA-1 hash of the CHD. After converting to ISO, disable compression (rebuild an uncompressed CHD from the ISO) and compare hashes.
Result: A 4-core CPU converts 4 CHDs simultaneously, reducing total library conversion time by 70%. If command line isn't your style, using a GUI is objectively better for usability. The best tool is NamDHC (formerly CHD GUI).
This leads to the common quest:
