Original URL: http://www.theregister.co.uk/2009/11/03/wd_s25_drive/
WD dives into SAS enterprise drive pool
And then there were three
Western Digital has jumped into the enterprise-class hard drive market with a 10,000rpm, 300GB capacity drive.
The WD S25 is built on WD's popular Velociraptor drive base, having a similar 2.5-inch form factor, spinning at 10K and with a capacity of up to 300GB.
The capacity points are 150GB, with one platter, and 300GB with two platters. There is a 16MB cache.
It has a 6Gbit/s SAS interface and is thus similar in specification to Seagate's Savvio 10K.3 and Hitachi GST's C10K300. The S25's transfer speed for sustained sequential data, WD says, is up to 128MB/sec. Hitachi GST's C10K300 does it at up to 143MB/sec whilst the Savvio 10K.3 transfers similar data at up to 129MB/sec.
The WD and HGST drives drives both have a 1.6m hours mean time before failure (MTBF) rating. Seagate doesn't provide a Savvio 10K.3 MTBF figure but does say its non-recoverable error rate is 1 in 10 to the power 16, the same as for Hitachi's C10K300.
The S25 is available to OEMs now and shipments are already underway, WD says, to the two largest OEMs in the industry.
Tom McDorman, the VP and general manager of WD’s enterprise storage business unit, confirmed what everyone expected: "This first product is the foundation upon which we will expand into the previously untapped traditional enterprise market."
Apart from generational increases in S25 capacity, the two obvious possibilities for expansion are, firstly, to increase the 2.5-inch drive's speed to 15,000rpm, and secondly to expand into the larger capacity, 3.5-inch form factor space. With its existing 3.5-inch SATA drives forming a potential base, adding an SAS interface to them shouldn't stretch WD's engineers too much.
A Fibre Channel interface is also a possibility, although the longer term future of this interface is one of declining use because of the advance of SAS.
Adding a 15,000rpm motor to the S25 unit would involve mechanical and electrical engineering effort, as WD would have to figure out things like vibration damping, efficient power consumption, and reading and writing data with a faster moving disk surface.
These thoughts suggests an enterprise 3.5-inch drive would be next.
Storage array and array subsystem suppliers now have the happy prospect of having three credible suppliers competing for business in the SAS enterprise drive market, with all that implies for pricing and supply flexibility.
There is, or should be, more information about the new drive here . ®