After years of using a mixture of internal and external drives with my MacPro, I have finally decided to streamline things and get a desktop RAID array to protect my data. I currently only have about 5TB, but want to put together something that I can grow into if possible. As average users accumulate large amounts of data, audio and video and move away from removable disc media, I think this subject will be of growing interest to many. This area is new to me (especially a RAID array, which I have never dealt with before). So, with that in mind, Im going to layout what Ive come up with so far (along with some questions) and see what people think. As always, any help, suggestions or warnings are most appreciated. Of course, if this topic has already been discussed or if someone knows of a source of information that would be useful, please be so kind as to let me know about it. I like to do as much research as I can on my own and only ask questions where needed. Here we go: MY COMPUTER MacPro 2 x 2.66 GHz Dual-Core Intel Xeon Memory: 2 GB 667 MHz DDR2 FB-DIMM OS X 10.6.8 INTERNAL DRIVES I plan to fill three internal drive slots with 3TB drives and transfer the data off my other drives. The ones I think I want to get are Western Digital 3TB Caviar Green drives. I know they spin at 5400RPM, as opposed to 7200, but these drives are mostly for storage and a lightning quick loading time is not essential for when I do need to access them. DESKTOP RAID ARRAY Here is where I get somewhat lost. I know that I want to have the capacity to backup 12TB using at least RAID5 and have it work with Time Machine. I am aware of Thunderbolt, but it is too new to be of any use to me now. Ideally, Id like to get a RAID enclosure that has both a FireWire AND a Thunderbolt connection so I have the opportunity to take advantage of Thunderbolt in the future. However, since my RAID array is for backup only with Time Machine, lighting fast transfer rates are not crucial. I have a number of questions regarding RAID and how to do this: 1. I believe that what I want is RAID5, but perhaps something else would be better suited for my situation. I want to be able to survive one, perhaps two, drive failures. 2. I would like to get an array that can backup a max of 12TB from the drives in my MacPro. I know that the RAID level I choose determines how much capacity I will need the array to have. Does such a large capacity exist for desktops? 3. In general, do you have to use certain types/brands/capacity drives in a RAID enclosure or can you drop in anything and have it work? Ive read contradicting information, so Im a bit confused on this one. Well, thats about all I can think of right now. Im sure Im missing some crucial question or leaving out a vital piece of information. However, I hope Ive provided enough detail to let you know what Im trying to accomplish. Any help, suggestions or warnings are most appreciated. Thank you.