Western Digital today announced 2 new “mobile” 2.5′ drives. The WD Scorpio Blue 750 GB and 1 TB drives are both shipping. Here’s the official word from WD.

WD Scorpio Blue 750 GB drives (model WD7500KEVT) are available now through select distributors and resellers; the 1 TB capacity (model WD10TEVT) is available now configured into My Passport Essential SE USB drives. The . . . MSRP for the WD Scorpio Blue 1 TB drive is $249.99 USD and for the 750 GB version it is $189.99 USD. WD Scorpio Blue hard drives are covered by a three-year limited warranty. More information about WD Scorpio Blue mobile hard drives may be found . . . at http://www.wdc.com/en/products/Products.asp?DriveID=685.

These are both 12.5 mm drives – too thick to fit into most notebooks – hence the quotes around “mobile.” But I’d love to get one into a LaCie rugged drive case.

2.5″ is coming of age
2.5″ drives are catching up with 3.5″ drive capacity. 5 years ago the highest capacity 2.5″ drives were about ¼ or less the capacity of the largest 3.5″ drives. In last couple of years that closed to around â…“. With this announcement that gap closes to ½ – until the next 3.5″ announcement.

This has more to do with vendors disengaging from the 3.5″ form factor than anything magical about 2.5″. As consumers buy more notebooks, more higher-margin notebook drives are sold. This is factored into R&D budget reviews and the investment dollars flow to the smaller form factor.

The StorageMojo take
Drive vendors are wondering how they can move the enterprise to the smaller form factor without losing the margins they enjoy on “enterprise” drives. Vendors have relied upon drive rpm, interface, MTBF and unrecoverable read error rate to differentiate enterprise from consumer.

All 15k drives have used 2.5″ platters for years. FC drive interfaces won’t make the jump to 2.5″ and 6 Gbit/sec SATA provides a lot of bandwidth. MTBF numbers face warranted criticism. SATA URE rates need improvement as capacities climb.

Perhaps the 12.5mm – or Savvio’s 14.5mm – form factor is key. With more height comes mechanical advantages that can be important to the enterprise: performance; capacity; reliability. And in a form factor that notebook vendors won’t embrace.

However that develops, congrats to WD for getting these to market first. My 3.5″ drives are looking as clunky these days as 5.25″ once did.

Courteous comments welcome, of course. Hey, drive engineers, how about helium-filled enterprise drives? Lower power, lighter weight (LOL), less heat and maybe even more rpm from the same platters. Pete, can your guys comment?