Looks can be deceiving. Take Hitachi GST's recent additions to its Travelstar line. The 2.5-inch drives may not look that much different than other small form factor drives, but one glance at their specs is enough to see the beginning of a storage revolution away from 3.5-inch drives.

In fact, although the recent Travelstar announcement was planned to coincide with CES, Hitachi's two new drives -- the Travelstar 5K500 and the Travelstar E5K500 -- will likely have an even greater impact on the enterprise.

Spinning at 5,400 RPM (rotations per minute), each drive offers 500GB of capacity -- a new record for this class of drives. Moreover, much like their faster Travelstar (E)7K200 7,200 RPM cousins, the drives can be equipped with built-in encryption. Because of this, the new drives will soon become the favorites of notebook vendors.

The first such vendor to deploy the new Hitachi GTS technology is Asus Technologies. Asus will offer the Travelstar 5K500 on two desktop models, the M50 and the M70. And if 500GB is not enough for you, the M70 can be equipped with two drives.

That's right: 1TB on a laptop, another industry first.

But there's more.

As you may know, the "E" in Hitachi drive parlance means "enhanced." As such, as opposed to the 5K500 used in the Asus laptop, Hitachi's new E5K500 offers features that make it more suitable for corporate deployment.

For example, the E5K500 doesn't slow down when exposed to vibrations created by other devices in the same chassis, making the drive a good candidate for deployment in a blade system or storage enclosure.

Because they ship in February, I haven't taken the drives for a spin quite yet, but some simple math on their specs yields interesting results. For example, the E5K500 has the highest capacity-to-volume ratio of any Hitachi drive I know, with about 57MB per cubic millimeter, more than four times better than the Deskstar E7K500 and more than double the capacious A7K1000 -- two 3.5-inch drives with 500GB and 1TB of capacity, respectively.

Another interesting bit of info: Considering only the power used when the drive is idle but ready to start kicking (Hitachi calls that state "performance idle"), the E5K500 is again a winner with the lowest watt-to-GB ratio, 0.004; by comparison, the Deskstar E7K500 and A7K1000 swallow more than twice and almost five times as much juice, respectively.

What those numbers mean is that the new drives from Hitachi -- and similar models from other vendors that will likely follow -- are a less bulky, more energy efficient replacement for comparable 3.5-inch SATA devices.

If those benefits are of interest to you, start asking your storage vendors for arrays built around those drives. The small drives may not cover all your requirements right now, but advances await. After all, putting yourself in a position to capitalize on more energy-efficient storage continues to be of paramount importance. Happy 2008!