I have a 1.8 GHz PowerPC G5. my memory is 1.5 GB DDR SDRAM. I recently installed the new system and now my computer is slow so I need to pump it up! Do my numbers show the reason it's been slow? I went on the apple website to buy memory, but I don't see my computer on the list and I'm not sure if PowerPc is the actual name of my computer. I don't think it's Intel or iSight based, but I have no idea how to figure it out. It's 3 years old.