This question often comes up and is a tough one to answer. There really is no accurate way to benchmark an Apple G4 vs. a Centrino-based PC, since both run a different OS. Rest assured though that should you choose to go with any of the new PowerBook models (1.33 GHz and above,) you will no doubt be completely satisfied from the raw performance in comparison to a Centrino-based PC.

Both types of machinines (G4 or Dothan-Centrino) are significantly fast at just about anything you throw at them these days. One plus with the Mac though - 768MB of RAM under Mac OS X Panther is like a gig under XP!