Vendors Releasing Ultra160 Drives, Launch Web Site

The SCSI Trade Association produced an Ultra160/m SCSI specification about a year ago, now several vendors are bringing compliant lines of disk drives and host adapters to market.

The SCSI Trade Association (www.scsita.org) produced an Ultra160/m SCSI specification about a year ago, now several vendors are bringing compliant lines of disk drives and host adapters to market. To serve as a promotional and educational tool for those interested in Ultra160 SCSI technology, an official Ultra160 SCSI Web site (www.ultra160-scsi.com) was launched last month with help from the SCSI industry.

The most prominent advance of Ultra160 is that the technology has twice the data transfer rate of existing SCSI offerings. This is expected to help in a storage market segment that faces mounting competition from Fibre Channel. The "m" from the initial nomenclature Ultra160/m SCSI has been dropped due to complaints from IBM Corp. and Compaq Computer Corp.

Quantum Corp. (www.quantum.com) is currently shipping its Quantum Atlas 10K and Quantum Atlas IV hard disk drive families with support for the Ultra160 interface. Western Digital Corp. (www.westerndigital.com) announced that its WD Enterprise 10,000 RPM low-profile hard drives with the new Ultra160 SCSI interface will be available this month in the OEM and distribution channels. IBM will release in the fourth quarter an Ultrastar hard disk drive line that incorporates Ultra160. Finally, Adaptec Inc. (www.adaptec.com) will be shipping SCSI host adapters using Ultra160 sometime late this year or early 2000.

At 160 MBps, analysts say the latest SCSI specification can offer performance levels equal to, if not greater than, Fibre Channel. The Ultra160 specification calls for inclusion of three major Ultra3 SCSI technologies: double-transition clocking, CRC and domain validation.

Double-transition clocking allows systems to run faster by doubling the amount of data transfer without increasing clock frequencies. CRC provides extra data protection for marginal cable plants and external devices, ensuring integrity of transferred data. Domain validation tests the storage network to gauge the right transfer speed.

Some vendors of SCSI drives have been reluctant to move from Ultra3 SCSI to Ultra 160. The requirement to be Ultra3 compliant is to include one of the Ultra3 technologies, while Ultra 160 requires the inclusion of the three previously listed. Other Ultra3 technologies include packetization and quick arbitration and select (QAS), but they won't be available for at least a year or two.

In addition to doubling the Ultra2 SCSI data transfer rate, products incorporating Ultra160 can test and manage a storage network. The test ensures that the maximum reliable data transfer rate is used. If reliability is believed to be at risk, the bus will be slowed to a rate that is considered to be reliable. This host adapter intelligence is expected to provide more system autonomy and less IT manager involvement.

Robert Gray, research director of storage systems at International Data Corp. (www.idc.com), says SCSI is facing new challenges because it continues to aim for all storage markets, low-end and high-end. "So now it's being nibbled on at the higher end by Fibre Channel and at the lower end by EIDE [Enhanced IDE]," he explains. "That said, there's still an awful lot of SCSI being shipped."

Vendors supporting the Web site and the SCSI effort include Adaptec, Andataco/nStor (www.nstor.com), Compaq Computer Corp., Fujitsu America Inc., IBM, LinFinity Microelectronics Inc. (www.linfinity.com), QLogic Corp. (www.qlc.com), Quantum and Western Digital.