Only by comparing two Seagate Barracuda 7200.8 hard disk drives with different interfaces we can finally see Native Command Queuing in action – it proves very smooth and hardly visible. Just like the first revision of Maxtor DiamondMax 10, these HDDs process writes together with reads, however, the lazy writes are very conservative without any data accumulation in the buffer and the requests rearrangement efficiency is minimal.

NCQ became much more expressive in the next Barracuda generation, although, it stopped working with writes. However the models with 16MB buffer lost lazy writing almost completely in case of non-sequential requests, and moreover, the NCQ efficiency was getting almost null. This is very interesting, almost as interesting as Maxtor’s metamorphosis described above. Well, these two companies seem to have found one another, hopefully their jointly developed solutions will surprise us again one day.