HDTune tests a similar level of features as compared with HDTach, but with a different access pattern. Thus provides us with an additional set of benchmark numbers to compare between storage configurations. Here we can get the minimum, maximum and average transfer rates as well as the burst rates and access times. CPU utilization has proven negligible with modern processing horsepower, and is no longer included.
HDTune's burst test gives inconsistent results. Posted here for information only.
All modern SSDs have no issue saturating their SATA 6Gb/sec link. No difference here with the M550's.