Forget ATA vs. SCSI vs. Fibre Channel. When it comes to disk drives, suitability for enterprise or desktop applications has little to do with the interface, but with the drive's underlying mechanical platform, says David Reinsel, research manager at IDC.
At least, that's one fact made clear by the introduction of Western Digital's new Raptor 36GB drive, which has neither a SCSI nor Fibre Channel interface, but Serial ATA (SATA). At 10,000 rpms, though, and with a 5.2 ms seek time and 1.2 million hour mean time between failures (MTBF) rate, the new drive clearly "parallels SCSI drives in terms of performance and reliability," says Steve Wilkins, Western Digital director of product marketing for enterprise products. All that, for 30% less than a comparable SCSI drive.
Prior to the Raptor, WD hadn't competed in the enterprise drive segment for a number of years. "We recognized that it was not our forte," Wilkins says. The new SATA Raptor drive "represents an opportunity for us to regain the enterprise market."
But while "ATA drives are getting more sophisticated, they're still nowhere near what SCSI can do," says Marc Noblitt, product planning manager at Seagate, which makes both SCSI, ATA and now SATA drives, with its Barracuda SATA V. Beyond interface, some of the design differences that set enterprise drives apart from their desktop counterparts include better thermal dynamics, stiffer and lighter--hence more resilient--actuator arms, longer testing cycles, and additional firmware, such as support for tagged command queuing with a 256-command queue depth.
That said, Seagate recently announced that its SATA drives will natively support command queuing, albeit with a queue depth of 32.
Despite the limitations of your average desktop drive, parallel ATA has already made some inroads into enterprise drive shipments. Depending on who you talk to, ATA drives made up between 5% to 10% of the market in 2002. IDC expects that number to double in 2003, if you group ATA and SATA drives together.
IDC's Reinsel does not expect WD's Raptor to dramatically alter the dynamics of the market this year, and for the time being, thinks Seagate probably "won't bring to market a 10,000 rpm SATA drive," says IDC's Reinsel, so as not to cannibalize SCSI drive sales. Although, if WD's Raptor does well, "they'd probably rethink that."