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Now let’s examine the data-transfer graphs and say a few words on the zone distribution. The models of the highest capacity come first.



HDS722525VLAT80 200GB

Now, that’s the answer! The capacity of the senior Serial ATA model is higher than of its ATA analog. To be exact, the ATA model was cut down to a round number of 250 billion bits – Hitachi has never behaved like that! Like IBM before it, Hitachi used to give the user a little bit more and its drives used to be a few gigabytes larger than the competitors. This time around, however, the two senior models are shortened, but the rest of them are not. That’s where the record-breaking average access time comes from – the cutting-down of some of the tracks reduces the distance of the actuator’s movements, i.e. it leads to a smaller average access time. We’ll keep this in mind when discussing the test results below.

To all appearances, the 200GB model is made by disabling one of the six surfaces of the 250GB drive. The resulting capacity was also truncated to a more or less round number of sectors. The graphs of the rest of the 7K250 series drives didn’t bring any surprises, save for one. Just take a look at THAT:

HDS722580VLAT20 60GB

The stretched shape of the graph suggests that this model is made by cutting down one fourth of the available tracks of the HDS722580VLAT20, and its name also bears an inkling of that. The very low speed makes us suspect that the longest tracks were dismissed, but the comparison of the zone distribution doesn’t reveal similar areas, and the average access time of this model doesn’t differ greatly from the others. Thus, the 60GB model (by the way, it is not mentioned in the specs) has an individual zone distribution. But why did Hitachi choose such a low sector density? For comparison, here’s the read graph of the first Vancouver with an areal density of 40GB/platter.


The age of this model is almost 3 years, but it has a higher linear speed than the mutant called HDS722580VLAT20 of 60GB capacity! By the way, due to certain confusion in the nomenclature of the drives, we will call the devices not by their model numbers, but by collective names like follows:

So, let’s start our traditional cycle of tests to determine the operational properties of the hard disk drives.

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