For most things I would think the Pentium D would win... Apple stuck with the G4 for way to long because they had to many production problems with G5 that it wasn't as widely used as it should have been... The G4 was out about the Same time as the P4 and they were tight competitors. The Pentium D probably will win in most tasks... Not to say the G4 was a slouch it was just kept longer than it should mostly because of failures from Motorolla and IBM