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What’s New?

First of all, the model numbering system has changed. Instead of the hereditary IBM nomenclature, Hitachi Global Storage has started to use a unified naming system for all its products:

The letter V in the Generation Code field most probably corresponds to the product’s codename – Vancouver.

The new series is declared to include models of 40, 80, 120, 160 and 250GB capacities with 2MB or 8MB buffers and two interfaces (ATA and Serial ATA). The Deskstar 7K250 inherited all the traits and features of its ancestor (aluminum rather than glass platters, fluid-dynamic motors), but has a higher platter capacity and support of the Serial ATA interface.

The series still includes “low-profile” models with a slightly slower seek time. Curiously enough, the seek time info in the press release (8.5 and 8.8 milliseconds) differs somewhat from the numbers in the specs. We think that the press release is closer to reality, but we’re going to check that out soon.

This time Hitachi didn’t limit itself with two track density variants (the Deskstar 180GXP series featured low-TPI versions of the drives), adding one more. The maximum density is only employed in the flagship models of 250GB capacity as it requires platters with a capacity of slightly over 80GB (83.4GB, to be precise). Platters with a reduced track density are used in single-platter models designed in the “LP” case.

  

For comparison I offer you snapshots of the senior Serial ATA model in the ordinary case. To avoid any misunderstanding I want to emphasize the fact that the type of the case has no connection to the interface type (ATA or Serial ATA), but only to the number of the platters in use.

  

So, the LP case looks more fragile than the ordinary one – it doesn’t even have a heat-spreading plate. We can’t call this fact anything else but “extreme economy on junior models”.

The electronics PCB of the Serial ATA model carries the well-known “serializer” from Marvell, i.e. this protocol isn’t native, but is artificially implanted.

The declared acoustic characteristics exactly coincide with the data on the Deskstar 180GXP.

The fluid dynamic bearings have reduced the noise of the single-platter models most of all whereas the noise reduction is negligible with the three-platter drives. This is true in practice: the single-platter Deskstar 7K250 is among the best in the idle noise parameter, but I can’t say the same about the 80GB and bigger models. The seek noise from their actuators is strong, sharp and “clicking” in the performance mode. Moreover, the typical special effects of IBM drives, unheard of by owners of HDDs of other brands, are still here. It’s hard to describe them in words. Some people call these sounds “meowing”, others – “shrieking”. These sounds occur quite often, they are oscillatory and very annoying, but they don’t affect the operability of the hard disk drive. Interestingly, these sounds are much louder in the LP case.

What’s new in terms of power consumption? Almost nothing, save for a much bigger appetite of the Serial ATA models on the +5v line.

One parameter looks strange in the specification: 128 segments in the read buffer are superfluously high, so we really doubt this number. Well, we’ll check this number out in practice soon.

There’s only one characteristic left to discuss. It is not emphasized by the majority of the manufacturers, but it does seriously affect the performance of a hard disk drive. We mean the number of servo identifiers per track.

 
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