This is a version of God of War 2 for PS2 emulators (PCSX2) or real PS2 consoles with OPL/USB/HDD. The game has been converted to CSO (compressed ISO) or archived with maximum ZIP/7z compression to reduce file size while maintaining playability.
Developers use algorithms to strip away redundant data. When you download a highly compressed ISO, you are getting a file that has been repackaged using tools like or 7-Zip at maximum ratio. Some repacks even remove dummy data (empty filler used to position data on the original disc for faster read speeds). When you extract it, the full 8.5 GB ISO is reconstructed on your hard drive.
That being said, if you still want to explore compressed PS2 ISO options:
Because the file is compressed, your CPU (Central Processing Unit) has to work harder to decompress the game data in real-time while also emulating the PS2 hardware. Here is a breakdown:
Many sites offer versions compressed to under 1 GB or even a few hundred MBs. How it's achieved: These reductions often involve