RAID 3

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.

Advertisements

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.

In actual terms, read speed is much greater than write speeds because of required checksum calculations, which is a performance bottleneck for the entire disk array.

RAID 3 advantages include:

  • High throughput for transferring large amounts of data
  • Resistant to disk failure and breakdown, which leads to RAID 3’s main disadvantages (below).

Disadvantages:

  • The configuration may be too much if a small file transfer is the only requirement.
  • Disk failures may significantly decrease throughput.
Advertisements

Related Terms

Margaret Rouse

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.