The game file type is important because it helps the emulator read and run your PS2 games. ISO, CHD, and CSO are three common game file types. ISO is the original game disc image and preserves all game data exactly as it is, without reducing its size. CHD is a compressed file format that reduces the game’s file size while still keeping the full game inside. CSO is also a compressed file that reduces the file size differently. All three formats have the same game content, but they store the data in different ways, which can change the file size and how the emulator loads the game.
What Is ISO Format in AetherSX2?
ISO is the most common and original game file format used in AetherSX2 for PlayStation 2 games. It is a complete copy of the original PS2 disc saved as one file, and it keeps all the game data the same without any compression. Because it is not compressed, ISO files are usually larger in size compared to other formats. The emulator can read ISO files directly, so they are simple to use and work smoothly with most games, but they take more storage space on your device.
What Is CHD Format and How Does It Work?
CHD (Compressed Hunks of Data) is a game file format that makes PS2 games smaller in size and is supported by AetherSX2. It reduces the file size without deleting any important game data. CHD works by compressing the original ISO file into a smaller file, so it takes less storage space on your phone. Even though the size becomes smaller, the full game is still complete, and the emulator can read and run it normally. This makes CHD a good option for saving storage while keeping the game working properly.
What Is CSO Format?
CSO is a compressed version of an ISO game file that makes the file size smaller to save storage space. It keeps the full game data but reduces the file so it takes up less space on your device. In AetherSX2, CSO files may work for some games, but the emulator has to unpack the file while the game is running. Because of this, the game may load a little slower compared to ISO files. CSO is mostly used by people who have less storage space and want smaller game files.
ISO vs CHD vs CSO – Main Differences
| Feature | ISO | CHD | CSO |
| Full Game Data | Yes, keeps everything exactly like the original disc | Yes, keeps all data while compressing | Yes, keeps all data while compressing |
| File Size | Large | Smaller than ISO | Smaller than ISO, usually smaller than CHD |
| Compression | No compression | Compressed into smaller parts | Compressed differently to reduce size |
| Storage Use | Uses more space | Saves storage | Saves most storage |
| Performance | Fast, no extra processing needed | Fast, slightly less than ISO | May load slower because the emulator decompresses on the fly |
| Compatibility | Works with all games | Works with most games | Works with many games, but some may have issues |
| Best Use | If storage is not an issue | If you want smaller files but full game | If you have limited storage space |
Which Format Gives Best Performance in AetherSX2?
For performance in AetherSX2, ISO files usually work the fastest. ISO is a full, uncompressed copy of the PS2 game, so the emulator can read it directly without doing extra work. CHD files are a little slower because the emulator needs to read the compressed parts, but the difference is small. CSO files can be slower for some games because the emulator has to unpack the file while the game is running, which can make loading a bit longer. So, ISO files give the smoothest and most stable performance for most games.
