Right now, my MacPro just has the 300gb sata drive that came with it. plus an external 1TB FW drive. Thinking about leaving OS and Apps on boot drive and adding new drive(s) for data. Then possibly change the boot drive to SSD in the future. For now, using CS4 and LR2, would performance be better if I added 2 internal 500gb drives and Raid-0 for storing all data. Or, not use Raid 0 , and use one for data, and one for scratch disc ?