Western Digital Caviar AA

Photo by kind permission of Western Digital.

Western Digital Caviar AA

WD went through some tough times in 1999. The years started with the ink still wet on the much-trumpeted design and component supply agreement with IBM. the majority of that year's Western Digital drives were rebadged IBM designs, with the Expert line leading the charge into the world's Editor's Choice awards. But then everything changed.

Despite having an excellent range of award-winning products, WD's costs were too high and the company was loosing a lot of money. The first thing to go was the very expensive speculative foray into the SCSI market. SCSI was a high-cost, low-volume market with too many suppliers already, and trying to carve out a slice of it against the established players had always seemed ambitious.

Next up was the recall of thousands of 1999 model 102AAs to replace a potentially faulty batch of logic chips. (Not the same drive as the later 102AA — see the comment on WD's new naming scheme below.) People made a lot of fuss about this one, far more than was warranted, actually. To be sure, Western Digital had a problem with the quality of some third-party components, but on the other hand, the company acted promptly and responsibly to deal with it. In our book, that stands to their credit.

Then came WD's quiet return to doing its own design with parts sourced from independent suppliers. The Expert name was dropped, and all WDs, both 5400 and 7200 RPM, were now to be called "Caviar". For a while, anyway — because the next change was the introduction of two lines of low-end drive, called "Spartan" and 'Protege".

At around the same time, WD became rather secretive. They no longer made it easy to tell which drive was which. Consider the new WD model numbering scheme. The traditional Western Digital model number told you quite a lot about the drive. Take the AC35100. The name has four parts:

  • A is the interface, in this case, ATA (better known as IDE).
  • C is the family, in this case, a Caviar, their mainstream 5400 RPM range.
  • 3 tells us that the drive has three platters. In fact, with this particular example, it is a five head design, so one of the platters is only used on one side, though you can't tell this from the model number.
  • 5100 is the notional capacity in Megabytes.

Armed with this knowledge, you could immediately tell the approximate technology level, and thus the performance of a Western Digital drive from the model number alone. You can make an educated guess that the AC25100 will be faster than the AC35100, because it has fewer platters and thus higher areal density. In short, a simple, informative and logical scheme. Contrast it with the new WD numbering scheme, which would give both these drives the exact same name: WD 51AA — or, indeed, give the same name to the IBM-sourced 102AA of recall fame, and to this current drive.

The new naming scheme works like this: first comes WD for Western Digital, then the capacity in hundreds of megabytes (what a stupid choice of unit!), and finally a two letter code to indicate the class and interface. The first letter indicates the performance category: "A" for a standard 5400 RPM drive, "B" for a faster 7200 RPM unit, and "E" for their slower, cheaper economy-class 5400s. The second letter indicates the interface type: so far there are only two: "A" for ATA-66 and "B" for ATA-100. We assume that "C" will indicate Serial ATA when that arrives sometime in 2002 or 2003.

But for all our gripes, on the whole Western Digital continued to provide fast, reliable, modern drives, and these 2000 models remained very much on our list of favoured products. The WD102AA was an excellent drive which we would have sold more of had it not been for the availability of the even better Samsung SpinPoint V1020 (which meant that the WD102AA mostly just covered out of stocks as our second-line 10GB drive), while the 153AA, not having a direct competitor in its size class on our shelves, sold quite briskly.

Performance1.22ReliabilityAA1
Data rate234 Mbit/secSpin rate5400 RPM
Seek time9.5msBuffer
Platter capacity10.2GBInterfaceATA-66
102AA10.26GB2 GMR heads*
153AA15.39GB3 GMR heads***