New to Logic, running an Imac 2.66 with 4 gig ram, two years ago got sold my PT HD3 rig (needed the money), I understand PT well, most of the processing is done on the cards, but Logic runs entirely on the cpu. I see why people like Logic, although not as intuitive as PT, sound quality is good and compared with PT relatively cheap. The effects, for the money are outstanding. I'm not an itb guy, I did almost all processing outside PT, but it was great for editing and recording. Can you set Logic up to run totally on an external hard drive, like PT where it stores all audio and session files and accesses them as needed, or must these files always remain on the OS drive? I ask because right now my Logic 8 copies them to an external drive, but keeps another copy on the internal hard drive which I must avoid.