If you are setting up a specific device, let me know you are emulating on (Windows, Android, or Steam Deck) or which specific PS2 titles you are trying to compress. I can provide the exact toolchains and settings to optimize your setup. Share public link

to reduce original 4GB+ DVD images down to much smaller sizes, sometimes under 500MB. Key Features and Formats CHD (Compressed Hunks of Data)

A PS2 ISO is a byte-for-byte copy of a DVD. Key structural components:

Drag and drop your .iso.ecm file directly onto the unecm.exe application icon.

disable your antivirus to download "highly compressed" files.