chdman createcd -i "game.cue" -o "game.chd"

claimed they had discovered a way to compress PS2 ISOs into CHDs that didn't just save space—they preserved "latent data." According to the post, the PS2’s Emotion Engine often processed code that never made it to the screen, a digital subconscious buried in the bits.

Want to dig deeper? Check the official PCSX2 documentation for their latest CHD compatibility notes, or explore the r/Roms subreddit’s pinned guide for verified CHD conversion scripts.

: For those comfortable with scripts, you can use a .bat file to bulk-convert an entire folder of games. A common script used by the community is: for /r %%i in (*.cue, *.iso) do chdman createcd -i "%%i" -o "%%~ni.chd" .

CHD was originally developed for MAME (arcade emulation) but has been adopted by the PS2 community because it solves every issue inherent to ISOs.