RAID 0 will be faster, it gains speed as you add more drives. So 3 HDD in a RAID 1 will not be anywhere as fast as 3 HDD in a RAID 0. Because RAID 1 will still be mirroring and RAID 0 will be spreading data across 3 disk. Even if it was only 2 HDD, RAID 0 would still have better performance over RAID 1. (You even say it yourself) I don't see why people shouldn't choose it for performance, when it does offer the best performance. It's just not smart to save any critical data on the RAID 0 array in case of a disk failure. Your OS, a few games and some drivers is all you need on a RAID 0 array and thats nothing that can't be reinstalled. You fail to explain yourself and only contradict your first sentence.