A pro photographer friend told me he only has 4GB RAM in his Mac Pro (2006) and he feels it's enough for PS CS5 and Lightroom. He also does some audio work on it. He told me the optimum setup for an SSD scratch disk is 4 X RAM installed. I have 16GB in my Mac Pro with a 128GB SSD scratch disk. Just started using CS6 and the Mac Pro and I'm amazed at the performance increase over my recently deceased MDD G4. I do find myself waiting for auto option in the contrast adjustment, in fact the Mac Pro can open 150 of my PS files a lot faster than it can do this adjustment on 1 file. My friend scoffed when I told him I was thinking of adding more RAM. I typically work on batches of 10 MB PS files but also occasionally on larger files. I'm wondering how much RAM PSCS6 users around here typically have installed. Thanks for insights.