Test Results
Access Time
We used two Samsung flash SSD drives to check the access time on the mobile backplane when in RAID 1 or RAID 0 mode. (The two other devices connect the drives directly to the host controller and hence don’t have an impact on performance.) The impact on access time was noticeable, although almost irrelevant on the flash SSDs. Clearly, the Silicon Image SteelVine controller introduces some latency when implementing RAID.
Read/Write Throughput
We checked the throughput in RAID 1 mode and found only small differences when compared to running a single drive. Running a RAID 0 stripeset almost doubles the throughput for those looking for maximum transfer rates. Running the device over USB 2.0 limits performance to 28.8 MB/s maximum for reads and 21.6 MB/s maximum for writes, which is far less than USB 2.0 can achieve (~35 MB/s).
