Analysis

posted on 06 May 2008 15:58

Seagate expects to ship more 2.5-inch drives in the first quarter of 2009 than 3.5-inch drives. It also expects SAS to take over from Fibre Channel in the enterprise drive space, signalling a major transition in enterprise drive connectivity.

John Bornholdt, a Seagate mid-west territory sales rep has a graph he shows to Seagate customers showing crossover in Q1 09 and a near precipitous decline in 3.5-inch enterprise drive shipments. He excludes nearline drives from this; their 3.5-inch format, with the SATA interface, will continue because of its capacity advantages, currently 1TB product is available.

Bornholdt said that 2.5-drive adoption showed a significant uptick when Dell and HP selected them over 3.5-inch drives for their server storage. The reason, one reason, is the increase in IOPS from a shelf of 2.5-inch drives compared to the same shelf filled with 3.5-inch drives.

Seagate's view is the other server OEMs are making the same choice - they'll commit during the rest of this year - and that 3.5-inch FC drives in servers - DAS (direct-attached storage) - are effectively end-of-life.

Now, network storage vendors are readying themselves for 2.5-inch adoption because 300GB 2.5-inch SAS drives are coming later this year. For these customers the current 146GB 2.5-inch drive maximum is not enough. Seagate expects and hopes that 300GB will mark the tipping point for the network storage vendors.

Seagate expects to see 3.5-inch FC drive shipment numbers decline strongly with the end of 2011 seeing very low shipment levels and 2012 being the end-of-life time for the 3.5-inch FC drive format, and for FC itself as an HDD interconnect protocol.

Asked if Seagate would make 2.5-inch drives with the Fibre Channel (FC) interface Bornholdt said Seagate is considering it and may make some for legacy requirements.

Between the lines this means that the main enterprise server/storage OEM customers for Seagate are not telling it they need Fibre Channel drives. They like SAS because, a) one controller can handle both performance (SAS) and capacity (SATA) drives, and, b) SAS drives with the coming 6Gbit/s interface will out-perform 4Gbit/s FC drives. They can drop their FC controllers, simplify their storage products and save money.

There is zero requirement from these Seagate customers for 8Gbit/s FC drives.

We can now ask if the momentum and drive behind Fibre Channel will be decreased if the enterprise storage arrays move to 2.5-inch SAS for performance and stay with 3.5-inch SATA for capacity. The answer is probably yes but FC SAN fabrics are so well established that the loss of FC interface drives will not matter much to the longevity of the FC interface.

Regarding timing we could expect network storage suppliers to need about 12 months to evaluate 2.5-inch SAS drives and product shipments to start in late 2009. Xyratex is already working on 2.5-inch product developments and Compellent is expecting to use the resulting array product.

^{[Chris Mellor, editor]}