Hitachi's Deskstar 7K2000 HDD: 2 TBytes, Spinning More Speedily

A bit over a week ago, I pointed out that six months after introduction, Western Digital was still the only vendor manufacturing a 2 TByte 3.5" HDD in volume. As it turns out, I wasn’t exactly right; Seagate recently began selling a 2 TByte member of its Barracuda LP family, unveiled in late April. Seagate’s ST320005N4A1AS-RK, a four-platter (eight-head) configuration, spins at 5900 RPM speeds. WD’s WD20EADS four-platter product conversely doesn’t specify a RPM performance metric, instead relying on a nebulous ‘IntelliPower’ marketing monicker. The IntelliPower algorithm dynamically varies RPM to optimize speed-vs-power consumption at any particular point in time…unfortunately, WD won’t say what the peak platter rotation speed is on this particular product. I suspect it’s 5400 RPM or, judging from last week’s 2.5" HDD unveiling, perhaps even less.

What about higher rotation speed 2 TByte variants? As far as I know, Seagate’s ridiculously pre-announced 7,200 RPM drive still isn’t shipping. Hitachi’s the first to reach that vaunted threshold, with its just-announced Deskstar 7K2000 ($329 MSRP):

However, whereas the earlier-mentioned drives from WD and Seagate are four-platter models (i.e. 500 GBytes/platter), a close perusal of the above photo will reveal that the Desktstar 7K2000 is a five-platter (400 GBytes/platter, and 10-head) configuration. Impressively, Hitachi squeezed this abundance of magnetic media into the 3.5" HDD form factor’s standard 1.028 inch (26.1 mm) height. However, as with Hitachi’s four-platter 1 TByte HDD unveiled in early 2007, you should expect the Deskstar 7K2000 to on average burn more power than a future fewer-platter equivalent, with all other factors (total capacity, etc) being equal.

What’s with the platter-count discrepancy between manufacturers? Think about it; as a platter spins ever faster, it becomes increasingly challenging for the read/write head to discriminate between sequentially stored data bits. That’s fundamentally the reason why Hitachi’s 7,200 RPM drive needs five platters to deliver the same aggregate capacity as WD and Seagate’s slower-spinning four-platter competitors.

But of course, as with Moore’s Law for semiconductors, PMR (perpendicular magnetic recording) technology and other techniques over time enable HDD suppliers to squeeze ever-increasing bit counts onto a given-sized sliver of magnetic media. And in fact, within the same press release that launched the Deskstar 7K2000 is a hint as to where Hitachi will shortly be going next:

In addition to the new 2TB Deskstar 7K2000, Hitachi GST is also refreshing its high-volume desktop hard drive family. The new 7200 RPM Deskstar 7K1000.C family will deliver up to 500GB per platter, and will come in capacities of 160GB to 1TB…Volume production and worldwide availability of the new Deskstar 7K1000.C will begin in the current quarter.

With single-platter 500 GByte and dual-platter 1 TByte models due out before the end of September, a four-platter 2 TByte simplification of today’s Deskstar 7K2000 will inevitably follow in short order.