Let’s study the specifications first.
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The most interesting thing you can note in the table (except for the twofold increase in the cache buffer size) is the reduction of the read error rate. Introducing perpendicular recording technology into its top-end 3.5?HDDs first, Hitachi claims to have improved data storage security considerably. The error correction mechanism has been modified for the first time since the Deskstar 120GXP: the Deskstar 7K500 does not use ECC interleaving while the Deskstar T7K500 has a longer ECC symbol. This has helped reduce the amount of auxiliary information while providing the same user data recovery capabilities. Hitachi also claims that the five-platter design contributes to high reliability as well because it provides the desired disk capacity without using extremely high areal density.
On the other hand, more platters consume more power and, usually, generate more noise. Have they made any improvements in these aspects?
Yes, the engineers have reduced the idle power draw of the Deskstar 7K1000 in comparison with the 7K500 and 7K400 and redistributed the load balance between the +5V and +12V rails at reading/writing. The HDD consumes no more than 2 amperes even when it starts up. Interestingly, the Deskstar 7K250 proves to be the most economical drive when spinning up its platters, and the consumption currents are increasing with every new generation.
Some improvements are promised as concerns the noise factor. The five-platter Deskstar 7K1000 proves to be quieter than three-platter models from the previous generations both when idle and when seeking!
Having moved up, the label gives you the view of the more robust three-screw fastening of the heads drive (there are only two screws in the three-platter models). The electronics of the Deskstar 7K1000 differs but little from the previous five-platter generation except for an updated processor model.
This processor is also employed in the Deskstar T7K500 whereas the 7K500 uses the same processor as the Deskstar T7K250. The memory has a fetch time of 6 nanoseconds which corresponds to a frequency of 166MHz. The memory frequency and, obviously, the CPU frequency too, has increased with the release of the Deskstar T7K250 so we can expect the new models to have a considerable advantage over the 7K250 and 7K400.
The Deskstar 7K1000 is produced in two versions, 750GB (on four platters) and 1000GB (on five platters) but it’s also got two twin brothers. These are the CinemaStar 7K1000 that features support for read/write stream control commands and offers a quiet seek mode and the Ultrastar A7K1000 that features protection against vibrations and a faster seek in comparison with the ordinary 7K1000. The desktop version of the HDD lacks all these features and has a slower seek. The three varieties of the HDD all come with a Serial ATA-300 interface only, but Native Command Queuing is officially supported only by the server-oriented modification. Does it mean the Deskstar 7K1000 lacks NCQ? We’ll try to find it out with our tests because the acceleration sensors (VR1 and VR2) are soldered on our sample of the Deskstar 7K1000 even though the Rotational Vibration Safeguard technology is not declared for it!
