For those with Slim or Super Slim models, the only official way to play is through the . Playing PS2 Games on PS3: Everything You Need to Know
These early 60GB (PAL) and 80GB (NTSC) models use software to emulate the PS2 CPU but keep the PS2 GPU. They support about 90% of the PS2 library but may have minor glitches. How To Ps2 Games On Ps3
The easiest way to tell if your PS3 can play PS2 discs natively is to check the front of the console for . If it only has two, it cannot play PS2 discs without modifications. For those with Slim or Super Slim models,
These launch models (20GB and 60GB) contain the original PS2 "Emotion Engine" chip, offering nearly 100% compatibility with PS2 discs. How To Ps2 Games On Ps3