DEC ends proprietary disk interface in favor of SCSI-II

Electronic News, Oct 5, 1992 by Craig Stedman

MAYNARD, MASS.--Digital Equipment Corp. last week confirmed it is ending development of add-on disk drives using its proprietary SDI interface, a move that follows a year-long legal offensive aimed at forcing third-party vendors to phase out SDI-based devices.

DEC, which is now emphasizing SCSI-II as part of an OEM push expected to yield a 1.6GB 3.5-inch drive this week, said a new 2GB 5.25-inch unit being marketed for its own systems is the last planned member of its SDI-based RA drive family.

"You can get higher performance and bandwidth by moving to SCSI-II," said Susan Heon, product marketing manager for end user storage. "Essentially, the RA drives have reached their performance peak because of SDI." The proprietary interconnect, used mainly with mid-range and high-end VAX models, supports a 2.8 MB-per-second data transfer rate, compared to the 8-10MBps handled by SCSI-II.

Asked if the effort to get rival SDI drive vendors to phase out their products by year-end was driven by DEC's decision to stop using the technology, Ms. Heon said, "I don't know if that's anything we were really worried about."

DEC's storage group does plan to continue developing new drives using its DSSI small-system interconnect, That technology supports a 5MBps data transfer rate, making wholesale changes to SCSI-II less compelling, Ms. Heon indicated. DEC also has launched a DSSI-related licensing offensive against third parties, but that program would allow rivals to stay in the market.

DEC has not decided whether it will develop more tape drives using its STI interconnect, a companion to SDI.

On the OEM side, DEC this week is expected to add a previously-discussed 1.6GB 3.5-inch drive (EN, Aug. 31). While the drive is expected to give DEC a new high-end 3.5-inch capacity, its potential shipment lead is unclear since IBM's AdStar subsidiary reportedly plans to release its own 1.6GB 3.5-inch unit this fall. A higher-capacity 5.25-inch drive, perhaps approaching or even surpassing the 3GB mark, may also surface.

Ms. Heon, meanwhile, confirmed in general terms reports that DEC plans to make changes in its storage pricing policies. "We're definitely moving toward what I believe to be a much more competitive and rational pricing model," she said without elaboration. The changes, also apparently to be applied to networking and other commodity-type products, would reportedly lower prices and make them virtually non-negotiable. Discounts for low-volume resellers also may be eliminated, a move aimed at shifting them from DEC itself to larger VARs.

Pricing on the RA73, DEC's final SDI disk drive, is $9,600 standalone. It is also available in the company's DECarray 900 subsystem, priced at $45,000 with four drives and $330,000 with 40. Support for the RA73 was also added to the smaller DECarray 300, which can use both SDI and DSSI peripherals, and a $600,000 DEC RAID Plus subsystem was introduced with 48 RA73s in either striped or mirrored configurations, for 48GB of usable storage space.

DEC also brought out new 20-port and 48-port hierarchical storage controllers with 40 percent more throughput than previous versions. Those and most of the existing controllers are scheduled to get SCSI-II support in the Q193, when Ms. Heon said a promised line of SCSI-II end-user drives and subsystems would be released.