For years, the PlayStation 2 emulation scene has been governed by two massive truths: the library is arguably the greatest in gaming history, and the file sizes are a storage nightmare. A single PS2 game, like God of War II or Final Fantasy X, can easily consume 4–6 GB of space. For a full collection, you’re looking at several terabytes.
This is the headline feature. Depending on the game, CHD compression reduces file sizes by 30% to 50%. ps2 chd roms top
There is a satisfaction in organizing a CHD library. Instead of a messy folder of mixed file types, you have a uniform directory of single .chd files. It is cleaner for scrubbing (verifying file integrity) and easier to back up to cloud storage or smaller SSDs. The Rise of CHD: Why PS2 ROMs Are
Problem: My save states aren't working. Solution: Save states are finicky with CHD files if you change emulator versions. Always use "In-game saving" (Memory Card) for CHD files, not save states. Significance: The definitive stealth action experience
These compress incredibly well due to less dense data: