Benchmarks: Atto Disk Benchmark

OCZ claims a maximum read throughput of 480MB/s with the Arc 100 and we hit 460MB/s when working with 32K data. However, when moving to larger 128K test samples, performance slipped to 368MB/s.

The write results were similar to those seen when measuring read performance and while we hit 446MB/s (better than the advertised 430MB/s) in the 32K test, that dropped to just 346MB/s in the 128K test.