Performance in IOMark

We have employed this program, written in our labs, for our earlier reviews. Now we’ll use it again to have an insight into the internal world of hard disk drives.

The growth of the data buffer in the Deskstar 7K1000 is accompanied with a twofold increase in its segmentation at reading, which is good, but the read ahead distance has not changed. Moreover, the read cache is disabled in all the models with a data buffer larger than 8MB – data cannot be read from the buffer, it has to be extracted from the platters again. This modification seems reasonable considering the sophisticated caching mechanisms of modern operating systems, but the adaptive look-ahead read algorithms introduced in the Deskstar 7K250 drives with an 8MB buffer are forgotten for some reason and data is just being read into the buffer… only to be discarded due to the lack of read cache. This “innovation” coincided with the introduction of Native Command Queuing support into the electronics. Hitachi’s programmers seem to be still exploring IBM’s intellectual heritage and try not to mess anything up. We’ll see in the following tests if this conservative approach is justifiable.

Note that the Deskstar 7K250 is the unrivalled leader in average seek time among the 7200rpm IDE HDDs while the average seek time of the Deskstar 7K1000 is worse even in comparison with not the fastest of its predecessors. The increase in the number of servo marks per track must have been insufficient to make up for the increase of the number of tracks.

The results of the low-level tests allow us to make the following suppositions about performance of the Deskstar 7K1000 in comparison with its predecessors: its IOMeter results will be somewhat worse, but its performance in file-processing tests should be higher due to its higher linear speed and huge buffer that can be used for effective caching of writes. Now let’s perform one more unusual experiment.