I use a Mac G4 tower 867 GHZ and 1 Gig Ram. Processing is a bit slow on my large files but I imagine that I need at least 2 gigs RAM . Would increasing to say 1.5 or 2 GHZ really make much of a difference when working with Photoshop CS? I'd to quickly open two files and make side by side comparisions. I would especially like to hear from those who have made the transition from a G4 to G5 (not neccessarily the new intel machine).