Benchmarks: NAS Performance Toolkit
Intel's NAS Performance Toolkit simulates various workloads to gauge theoretical performance. Content Creation is primarily a test of random writes, Office Productivity is a read and write test involving hundreds of small files, Directory Copy from NAS is a read test that uses 2,833 files, while Photo Album is a largely sequential test of mixed-sized reads.
Performance understandably isn't quite as hot as some of the dual-bay RAID 1 alternatives, yet the numbers are solid for a five-bay setup housing 40TB worth of drives.