I have never used the software RAID option in Disk Utility in OSX. I have usually used hard ware RAID (NewerTech GMAX e.g.), but I have bought two Seagate 4TB drives and have set them up by making a RAID-0 8TB through Disk Utility. It seems to work ok and give me around 260 MB/s read/write. I am wondering about a few things that I hope someone can answer. 1. Can I add a Disk (third one) to the RAID-0 array without having to re-build? If so I am guessing it will have to be an identical Seagate 4TB? 2. What is the RAID utility in 'Utilities'? I use Disk Utility to build the RAID. When I try to open this App it says 'RAID Utility is not supported on this computer'. I have a Mac mini Late 2012 i7 2.6Ghz. 3. If I add a third identical 4TB drive, does OS X have RAID 5? Or if I add a third drive and rebuild I am guessing I will have 12TB but is the speed even faster as well? 4. Any other suggestions for my new 8TB setup? Sorry for basic questions but while I have years of experience with Mac/OSX I have never had much to do with software RAIDs. Thanks.