Hi, I have some questions about scratch disk: From my understanding, its best to use a second internal hard disk for your scratch disk. Problem is, notebook only has 1 hard disk. Im currently using PC and hopefully getting a MBP soon. So I will be using Fusion to run Photoshop. I was wondering should I make a third partition for scratch disk or use either an USB2.0 or FireWire(which is better?) external desktop hard disk for my scratch disk?. Also what happen if I didnt connect my scratch disk when I run Photoshop or Illustrator?