I'm tuning my MacPro 4,1 to fit a project to be edited in FCPX with 50+ hrs of footage in full HD. It's a 2.93 quad, 12GB RAM and stock GT120 video card, osx 10.6.8. The upgrade focus is on disk space and performance, and with the help of these forums and others, this is what I've come up with, and just before I splurge on 7 disks, I would like your experienced input about the soundness of the plan. For the performance part, I have in mind 3 x 2TB WD RE4 disks in RAID0 setup with disk utility, and 4 x 3TB WD RED for an external Drobo for backup only, via FW800 (already bought the unit). Then a Crucial M4 256GB SSD in DVD bay 2 as a boot + applications disk. I'm split as whether to go with 3 x 2TB RE4s or 2 x 3TB RE4s (almost same price), and thus win an extra internal drive bay. The machine is also being used for audio editing in ProTools 9, has 600 MB of recorded audio which needs to be available, and then there is a 500+ MB library of data/photos. I have a 2TB Black Caviar I intend to use for user/audio/data in drive bay 0, haven't had any issues with the 2TB single disk and the flow of audio. I tried a Radeon 6870 at some point, and was not impressed with its performance FCPX-wise, so I plan to stick with the stock card until stuck. My focus is on a responsive system that loads and handles all the footage nicely, and integral to this plan is to have an onsite daily backup to the Drobo, using CCC. Whaddya think?