Seagate Breaks the Areal Density Limit With 1 TB 2 Platter 2.5″ Drive

Storage capacity continues to move forward on both 3.5″ and 2.5″ hard disk drives. On the small form factor side, Western Digital was first with a 250 GB platter, then Seagate shot back with a 320 GB platter, then it was Hitachi at 375 GB. So it was only a matter of time until the magical half-terabyte mark would be reached, yielding 1 TB in a 2-platter drive. Now Seagate has done it, shipping a 2-platter 9.5 mm hard disk drive in their latest GoFlex portable case.

Two Platters is Magic

I already have a 1 TB 2.5″ hard disk drive from Seagate, and Western Digital was first to that party. But the makers pulled shenanigans to reach this capacity point, thickening the case to 12.5 mm or even 15 mm to accommodate three platters (or more!). This slight increase in thickness (or “z-height” in drive lingo) wouldn’t matter except for one important fact: 2.5″ hard disk drives are often used in laptops.

Portable computers prioritize compactness and power performance above all else. So two-platter 9.5 mm hard disk drives have become must-have, balancing capacity, performance, and cool running. Many laptops don’t have physical space for a 12.5 mm internal drive, let alone a 15 mm whopper like my Seagate.

So, although it’s nice to see capacity points like 1.5 TB reached in a 2.5″ small form factor hard disk drive, it’s not really relevant in the portable computer space. There, we have to wait for 2-platter drives like this new Seagate. Note that the company also introduced a mammoth 1.5 TB drive using three of these same 500 GB platters.

Note that increased areal density from 500 GB platters will bring increased performance as well. Throughput to this new drive should improve by about 30% for sequential operations, though this will be masked by the USB interface. I expect the eSATA version of this drive to fly, perhaps topping out over 110 MB/s even on a 5400 rpm spindle. USB 3.0 performance should be in this same vicinity, while USB 2.0 will strangle the drive, limiting it to about 30 MB/s.

External Only (For Now)

But we’ll have to wait a bit longer. Seagate’s first customer for the 2-platter 1 TB drive is (surprise) Seagate itself. For now, the only way to get this new drive is to buy their GoFlex 1 TB external portable drive, available now from major retailers as well as Seagate itself. We expect a new rev of the Momentum drive family shortly, followed by wider availability of the device outside a GoFlex enclosure.

You might want also to read Lemons Into Lemonade: Seagate Repackages SATA As GoFlex

Note that Seagate sells a few different drives in this space, and not all are created equal:

• The older STAA1000100 is a 3-platter drive in a 22 mm case. It’s cheap at under $120.
• This new drive is the STAA1000103, which comes in a 14.5 mm case. It’s pricier at over $179
• There’s also the new STAA1500100, which is a 3-platter 1.5 TB model in the thicker 22 mm case. It’s most expensive at $229, but just look at the size of it!

Both drives look similar, but it’s easy to tell them apart in person: The 22 mm case is noticeably thicker.

Note to Mac users: This drive is compatible with Mac OS X thanks to the bundled NTFS drivers and USB 2.0 compatibility, and you can always reformat it as HFS+. Seagate sells a FireWire 800 dock and cable for the GoFlex line as well. You might even be crazy like me and have eSATA on your iMac or MacBook. However, there is as of now no USB 3.0 support in Mac OS X. So most users will be stuck in the slow lane. Thanks, Apple!

Stephen’s Stance

Seagate’s new thin GoFlex 1 TB drive is impressive technologically, though I can’t imagine the average consumer would be willing to spend over $50 more to shave off 8 mm of thickness from a portable drive. The increased performance and reduced power consumption would be invisible to many of these buyers as well. Laptop users looking to expand internal storage should wait for a bare drive to be released.

But this new density achievement is important for the hard disk drive industry in general and Seagate in particular. It marks a new generation of storage devices, and the technology will certainly find its way into other products. A 1 TB Momentus XT hybrid drive would be especially tempting! I applaud Seagate for being the first to cross this line, and look forward to a hands-on test as soon as I can manage it.