The Sims 3 cannot run on a PowerBook G4. The hardware and OS requirements are fundamentally mismatched.
| Requirement | The Sims 3 (Mac) | PowerBook G4 (Max) |
|---|---|---|
| OS | Mac OS X 10.6.7+ (Snow Leopard) | 10.5.8 (Leopard) max |
| CPU | Intel Core 2 Duo / Core i-series | PowerPC G4 (1.67 GHz max) |
| GPU | 128 MB VRAM, Shader Model 2.0+ | ATI Mobility Radeon 9700 (64 MB, no SM2) |
| RAM | 2 GB+ | 2 GB max (DDR2) |
Keep the G4 for retro — play Sims 2. For Sims 3, you need an Intel Mac (2006+) or Windows/Linux.