Can PS3 Games Run on a PS2? No

No. It is physically and architecturally impossible.

Hardware Barriers

• Disc Format: PS3 = Blu‑ray (25/50 GB, blue laser). PS2 = DVD‑ROM (4.7/8.5 GB, red laser). PS2 drives cannot read Blu‑ray.
• CPU Architecture: PS3 = Cell Broadband Engine (1 PPE + 7 SPEs, 3.2 GHz, PowerPC‑based). PS2 = Emotion Engine (MIPS III, 294/299 MHz). Completely incompatible instruction sets.
• GPU: PS3 = NVIDIA RSX (550 MHz, Shader Model 3.0). PS2 = Graphics Synthesizer (fixed‑function, 147 MHz).
• RAM: PS3 = 256 MB XDR + 256 MB GDDR3. PS2 = 32 MB RDRAM + 4 MB eDRAM.
• OS/API: PS3 games target libgcm/PSGL on GameOS. PS2 games run bare‑metal on EE/IOP.

Reverse Compatibility (PS2 on PS3)

• Launch PS3s (CECHA/B/C/E, 20/60/80GB): Hardware EE+GS chips → native PS2 playback.
• Partial BC Models (80GB MGS4 bundle, 160GB): Software emulation (GS only) ~70% compatibility.
• Slim/Super Slim (2009+): No PS2 disc support. PS2 Classics (digital) only.

You can play PS2 games on a compatible PS3, but never the reverse.