Those HDDs, if single-actuator, spend around 2~4 MB of streaming potential per seek. That means, if you access files of exactly that size you'd "only" half you

Those HDDs, if single-actuator, spend around 2~4 MB of streaming potential per seek. That means, if you access files of exactly that size you'd "only" half your iops. HDDs are quite fine for data chunks in the megabytes.