Toshiba: Our 2.5-incher does the same job as a 3.5-incher

Toshiba sees life in fast 2.5-inch drives yet, and has followed close on HGST's heels by announcing a 600GB model spinning at 15,000rpm.

There are also 300GB and 450GB capacity points in this 24 x7 operation enterprise drive product set.

The two drives are pretty similar. Toshiba's AL13SXB has a 15mm z-height, meaning we believe, 3 x 200GB platters with a 341Gbit/in² areal density or higher. It has a 6Gbit/s SAS interface and features 512n and 4K sector lengths with 512e emulation. The drive streams out sequential data at up to 228MiB/s, or 243MiB/s for the long sector models. There is an AL13SXQ self-encrypting version.

The HGST Ultrastar C15K600 has a faster 12Gbit/s interface and a 128MB cache compared to the 64MiB of the Toshiba drive. It also has a quoted 528Gbit/in² areal density.

Both drives have a 2 million hour MTBF (HGST) or MTTF (Toshiba). Like HGST, Toshiba has doubled the capacity of a previous enterprise drive; in its case the MK01GRRB/R product.

In its announcement material Toshiba makes the point that its new 15K rpm 2.5-incher equals the capacity of a 15K 3.5-inch drive in a smaller form factor needing less power and enabling more spindles to be crammed into a rack enclosure. Again, like HGST, Toshiba is seeing a withdrawal from the market of 3.5-inch enterprise drives and their replacement by, both say, 2.5-inch drives or, as we all know, solid state drives which are more expensive per GB but much faster responding, especially for random data.

Toshiba says 15K hard disk drives are and will remain the mainstay of enterprise mission-critical storage operations to which thought we add "for a while yet." ®