RAID level summary
Compare RAID levels according to their capabilities.
The following information provides data redundancy, usable disk capacity, read performance, and write performance for each RAID level.
RAID level | Data redundancy | Usable disk capacity | Read performance | Write performance | Min/Max devices per array on PCI-X and PCIe controllers | Min/Max devices per array on PCIe2 and PCIe3 controllers |
---|---|---|---|---|---|---|
RAID 0 | None | 100% | Very good | Excellent | 1/18 | 1/32 |
RAID 5 | Very good | 67% to 94% | Very good | Good | 3/18 | 3/32 |
RAID 6 | Excellent | 50% to 89% | Very good | Fair to good | 4/18 | 4/32 |
RAID 10 | Excellent | 50% | Excellent | Very good | 2/18 (even numbers only) | 2/32 (even numbers only) |
- RAID 0
- Does not support data redundancy, but provides a potentially higher I/O rate.
- RAID 5
- Creates array parity information so that the data can be reconstructed if a disk in the array fails. Provides better capacity than RAID level 10 but possibly lower performance.
- RAID 6
- Creates array "P" and "Q" parity information so that the data can be reconstructed if one or two disks in the array fail. Provides better data redundancy than RAID 5 but with slightly lower capacity and possibly lower performance. Provides better capacity than RAID level 10 but possibly lower performance.
- RAID 10
- Stores data redundantly on mirrored pairs to provide maximum protection
against disk failures. Provides generally better performance than
RAID 5 or 6, but has lower capacity.Note: A two-drive RAID level 10 array is equivalent to RAID level 1.
- RAID 5T2, 6T2, and 10T2
- Each tier in the array follows the capabilities of the base RAID level of the tier, except that the total maximum number of devices in both tiers combined cannot exceed the max number of devices for that base RAID level.