Ultra160/m SCSI gains momentum
By Zachary Shess
Earlier this month, Quan-tum Corp. announced the availability of its 10,000rpm Atlas 10K and 7,200rpm Atlas IV drives, the first disk drives to ship with Ultra160/m SCSI connectivity.
The drives provide 36GB in a 3.5-inch half-height form factor, or 9GB and 18GB in a low-profile one-inch-high footprint. The Atlas IV has a 6.9ms average seek time and 257MBps maximum internal transfer rate. The Atlas 10K offers a 5ms average seek time with a 315MBps internal transfer rate.
Ultra160/m doubles the SCSI transfer rate from 80MBps to 160MBps by using both edges of the request/acknowledge signal to clock data. The interface adds Double Transition Clocking, Cyc-lical Redundancy Checks, and Domain Validation while maintaining backward compatibility.
Last September, seven vendors announced support for Ultra160/m. Since then, several vendors have announced product availability.
For example, Western Digital expects to ship Ultra160/m-compatible drives in September. On the adapter side, Adaptec is now shipping 64-bit, 66MHz two-channel Ultra160/m Trident II host bus adapters (HBAs) to OEMs, while QLogic earlier this year provided samples of its model 12160 HBA chips and boards.
On the testing side, Xyratex plans to have pre-production units of its Ultra160/m Talos testers in July, with volume shipments by September. And Mylex announced that it will ship PCI RAID controllers supporting both Ultra160/m and Ultra3 SCSI later this year.
Quantum officials maintain that extending SCSI capabilities broadens its disk drive line without displaying a lack of faith in Fibre Channel. "Fibre Channel makes sense when there`s lots of drives in the subsystem," says Skip Shapiro, product line manager in the workstation and systems storage group at Quantum. "For smaller scale subsystems, Ultra160/m provides plenty of bandwidth, lower costs, and a lower power drain."
Mark Fife, senior vice president of marketing at Andataco, in San Diego, agrees. Fife also expects Ultra160/m SCSI will be seen in some legacy enterprise environments, where IT managers are not anxious to migrate to Fibre Channel. While Andataco`s GigaSTOR/160 enclosure is the first external subsystem to support Ultra160/m, Fife says major server vendors are not far behind in offering Ultra160/m-compatible products.
"By mid-summer, I think you`ll see a number of server manufacturers offering 160/m controllers embedded on motherboards. So they`re clearly embracing it as a lower-cost alternative for small or medium business applications," Fife says.