Data striping without redundancy

Highest performance

No data protection; One drive fails, all data is lost

Disk mirroring

Very high performance; Very high data protection; Very minimal penalty on write performance

High redundancy cost overhead; Because all data is duplicated, twice the storage capacity is required

No practical use

Previously used for RAM error environments correction (known as Hamming Code ) and in disk drives before the use of embedded error correction

No practical use; Same performance can be achieved by RAID 3 at lower cost

Byte-level data striping with dedicated parity drive

Excellent performance for large, sequential data requests

Not well-suited for transaction-oriented network applications; Single parity drive does not support multiple, simultaneous read and write requests

Block-level data striping with dedicated parity drive

Data striping supports multiple simultaneous read requests

Write requests suffer from same single parity-drive bottleneck as RAID 3; RAID 5 offers equal data protection and better performance at same cost

Block-level data striping with distributed parity

Best cost/performance for transaction-oriented networks; Very high performance, very high data protection; Supports multiple simultaneous reads and writes; Can also be optimized for large, sequential requests

Write performance is slower than RAID 0 or RAID 1

Combination of RAID 0 (data striping) and RAID 1 (mirroring)

Highest performance, highest data protection (can tolerate multiple drive failures)

High redundancy cost overhead; Because all data is duplicated, twice the storage capacity is required; Requires minimum of four drives