NCQ has a tiny limit of a maximum of 32 commands. The absolute best case would probably be if you could submit a request for all the blocks in all the files in

NCQ has a tiny limit of a maximum of 32 commands. The absolute best case would probably be if you could submit a request for all the blocks in all the files in the directory at once to the hard disk, and let it figure out the optimal order in which to answer. But we don't have such a thing.