Articles: Storage

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The life of a hardware tester is never dull. First, Maxtor pleased me with an unpredictable variety of the stuffing in its products; then some inexplicable surprises came from IBM. Samsung has remained an island of stability but it doesn’t remain one anymore! And really, the previous SpinPoint P40 series was unassuming and simple and yet very reliable. It was a kind of classics of hard disk drive making. And we might have expected the same from the new SpinPoint P80 generation, yes? None of that!

The fierce competition makes the manufacturers go for various tricks to reduce the manufacturing cost of their products. There is a limit to simplifying any design, beyond which no hard disk drive would function properly, so they have to resort to the reduction of overhead costs. One of the most important operations performed over an assembled hard disk drive is factory formatting, the successful accomplishment of which determines the consumer qualities of this particular sample. For example, if one “head/surface” pair doesn’t comply with the specified characteristics, they just disable this pair to output a drive of a smaller capacity. If all the surfaces don’t fit into the norm, the device is defective, i.e. the manufacturer suffers a straight loss.

Of course, the manufacturing companies sought to avoid the situation when an already assembled device went to the trash bin; for example, they started pre-selecting heads with desired characteristics. Another approach, pioneered by Maxtor, employs formatting of disks for a smaller density. As you may remember, the last DiamondMax series used platters differing in their track as well as bit densities. It seems unlikely that different-capacity models of the one and the same series should be made of different parts, whereas formatting of platters for a unique density solves two problems at once: they can roll out junior models, much demanded by the market, and also utilize samples that turned to be non-operational at the maximum data density due to some reason.

Driven by this need to economize, Samsung has advanced further in this direction. This manufacturer developed a technology to format each head/surface pair for an individual capacity. And it seems like the bit density (sectors per track) and the track density (tracks per platter) may both vary on each surface of a drive! IBM employed a similar technology in its latest mobile HDDs, yet they only matched the number of sectors to each head and each density zone, but here we can even have different number of tracks! It doesn’t prevent the drive from functioning normally due to “per-track” rather than the “per-head” translation of the linear address (at sequential reading the heads move through the entire zone on one surface and then switch to another).

You may recall that this translation method was employed by the now-retired Fujitsu in its IDE drives, and it brought about the legends about their super-reliability. The trick was simple: if one of the heads of a Fujitsu drive failed, some data could still be restored in most cases, while “per-head translation” drives needed a complex operation of replacing the heads unit, without any guarantee as to the outcome.

The individual formatting technology was first used with SpinPoint V80 and P80 series, announced back on June 13, 2003. We will talk about the latter series, with 7200rpm spindle rotation speed, today.

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