What Does RAID 3 Mean?
RAID 3 is a Redundant Array of Independent Disks (RAID) standard that uses striping at the byte level and stores dedicated parity bits on a separate disk drive. Like RAID 2, RAID 3 requires a special controller that allows for the synchronized spinning of all disks. Instead of striping data blocks into different disks, RAID 3 stripes the bits, which are stored on different disk drives. This configuration is used less commonly than other RAID levels.
Techopedia Explains RAID 3
Because RAID 3 combines parity and striping with stored parity bits on a dedicated disk, this configuration requires at least three separate hard disks - two for striping data and one for storing parity bits. The disks must spin in sync, so sequential read/write (R/W) operations achieve good performance. However, random R/W operations may take heavy hits in performance.
