I know there are a lot of posts on this forum that address this question - but none of them really layout the best option for what I am looking for. I own a mac pro and do a lot of video editing on it. I currently have all 4 drive bays occupied with drives - but NONE are setup in a RAID. I have one for the OS / applications - one for a scratch drive - 2 for storage. Of course I would like to boost performance (primarily on the scratch) and also have backups for everything (except the scratch drive). My first thought was to buy an external storage unit that is a RAID and use it as the primary scratch and storage drive. Of course I would want a RAID 10 or 5. (I am no expert on RAIDs - so I could be totally wrong). But I need to save money anyway I can. So I thought - why not setup a RAID in the Mac Pro itself (perhaps have 2 drives set to a RAID 0) and have that be my scratch drive. Then I could have an extra bay for storage. That would only leave my having to buy a cheap external drive for backup. Can anyone give advice on what would be the best setup to meet all of my requirements? 1. I want a fast scratch drive (preferably on a RAID) 2. I want a backup of my OS and my storage 3. I really don't care about a backup for the scratch drive - as I take the raw footage and encode it into ProRes 422. I can toss the ProRes stuff when I am done with a project - but keep the raw files. 4. I want to achieve these requirements as cheaply as possible. Thanks for any advice offered!