This RAID level offers better write performance, increased data protection and faster rebuilds than RAID 5. Performance does not degrade as much as in a RAID 5 array because a single failure only affects one array. Up to four drive failures can be overcome as long as each failed drive occurs in a different RAID 5 array.
One disadvantage to RAID 50 is that it needs a sophisticated controller.
The best use case for RAID 50 is for applications that require high reliability.