f5771a61_12__Storage_Subsystem___Part_2__1
[0] · Double rotated parity, or double parity disks (RAID 6) [1] 
Traditional RAID 6 is basically RAID 5 with additional redundancy built in. Instead of a single block of parity per stripe of data, two blocks of redundancy are included. The second block uses a different redundancy code (instead of parity), which enables data to be reconstructed after the loss of any two disks. More complex implementations may take advantage of algorithmic or hardware optimizations to reduce the overhead that is associated with maintaining the extra redundant data.As far as power and performance, the same general statements can be made for RAID 6 that were made for RAID 5, but to a larger magnitude.
Performance Tuning Windows 2012: Storage Subsystem - Part 2
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