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.

Table 1. RAID level summary
RAID level Data redundancy Usable disk capacity Read performance Write performance Devices per array on PCIe3 adapters
RAID 5 Very good 67% - 94% Very good Good

Minimum: 3

Maximum: 32

RAID 6 Excellent 50% - 89% Very good Fair to good

Minimum: 4

Maximum: 32

RAID 10 Excellent 50% Excellent Very good

Minimum: 2

Maximum: 32

System mirroring Excellent 50% Excellent Very good Not applicable
RAID 5
Creates array parity information so that the data can be reconstructed if a disk in the array fails. This level provides better capacity than System Mirroring 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. This level provides better data redundancy than RAID 5 but with slightly lower capacity and possibly lower performance. It also provides better capacity than System Mirroring 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.
System mirroring
Stores data redundantly on mirrored pairs to provide maximum protection against disk failures. This level provides better performance than RAID 5 or RAID 6, but has lower capacity.