Considering the processor and with just 1GB of memory, the built-in hardware encryption engine does a decent enough good job of negating the effects of dealing with encrypted data. With the discs built into a RAID 5 array, it dropped 26MB/s when writing encrypted data to the NAS and 22MB/s when reading the data back. It's a bit more efficient when dealing with a RAID 6 array, with a 17MB/s and 16MB/s drop in writes and reads respectively.
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