If you want to save space without dealing with the hassle of extracting massive .iso files every time, consider looking into the format.
A standard PlayStation 2 game disc holds between 4.7 GB (Single-Layer DVD) and 8.5 GB (Dual-Layer DVD) of raw data. When these discs are converted digitally into standard .ISO files, they take up the exact same amount of space, even if the game data only uses a fraction of the disc. i--- Ps2 Highly Compressed Games Iso
: Converting standard .iso files into .chd (Compressed Hunks of Data), a lossless format natively supported by modern emulators. Popular Highly Compressed PS2 Games List If you want to save space without dealing