I'm getting the pb for university and for Logic. I don't really care about getting the .17 gigabyte increase in the G4, just about the difference i will get from the 128Vram. I've heard the Tiger will need a minimum of 64Vram. Is this true? If so, would buying the 128Vram make a huge difference because it is double? And for Logic will it help any? I don't play games much so i won't be using it there. What exactly does Vram do to help your system, when it is not making things look better?