PS2 emulation is demanding. Even with a "highly compressed" file, your phone needs muscle to run it. Here is how to optimize performance:
Modern Android devices face three bottlenecks when running compressed PS2 games:
Real-world tests with AetherSX2 show that running a highly compressed game (e.g., Shadow of the Colossus, original 5.7 GB → compressed 2.1 GB 7z) after extraction performs identically to uncompressed ISO. However, attempting to emulate directly from a 7z archive is impossible without full extraction, making “highly compressed playable” formats a misnomer.