Ok, so I know the scratch disk has been covered a lot, but for my particular setup I'm getting mixed information... I'll be running OSX and all apps on a 60GB SSD drive, and all my other files on a 7200rpm HDD. Both internal SATA2 on a MBP. Which of these disks would be better to set up as the scratch disk? Adobe says not the boot disk and other sources say not the disk with the photos on it. So which will give me the best performance? Thanks! Bonus question: My 7200 is quite noisy and drain the battery. Will I see a significant decrease in Photoshop or overall performance if I downgrade the storage disk to 5400rpm?