Powerbook Split - DDR vs. DDR2

Telling DDR and DDR2 apart is difficult, because the differences are subtle. However, care must be taken because DDR2 will not work in DDR machines, and DDR won't work in DDR2 machines. To find out which you have:

about this mac Select "About This Mac" in your Apple Menu.
ddr sdram DDR SDRAM means you have the
PowerBook G4 Aluminum that runs DDR RAM.
ddr2 sdram DDR2 SDRAM means you have the
PowerBook G4 Aluminum that runs DDR2 RAM.