The conventional wisdom about NAS is that it's a storage system primarily for the small to midsized businesses
(SMB), the Remote Office Branch Office (ROBO) or even the Small Office Home Office (SOHO). The rationale being that it's simple storage for the storage-challenged administrator and lacks the IOPS, throughput, scalability and data protection of the more enterprise capable SAN storage.
Like most conventional wisdom, it's based on the past and not the present. In other words, the conventional wisdom is wrong.
New technologies and architectures are providing performance that is equal to or better than the best SAN storage arrays. For the best per NAS system performance there's BlueArc's Titan 2. It can demonstrate as much as 300,000 NFS IOPS or approximately 98,000 SpecSFS IOPS per system (600,000 NFS IOPS or 195,000 SpecSFS IOPS per clustered pair) and throughput as high as 1.25 GBps per system (2.5 GBps per clustered pair).
Read the rest of Marc Staimer's article at SearchStorage.com.