Terabyte Flirtations

After focusing its initial perpendicular recording efforts on diminutive 2.5" and 1" HDDs, Seagate has now turned its attention to the larger 3.5" form factor. On Tuesday, the company launched PMR (perpendicular magnetic recording)-based 15K RPM enterprise drives, in 3 Gb/sec SAS, Ultra320 SCSI, and 4 Gb/sec Fibre Channel interface options, and at capacities of up to 300 GBytes. And, if leaked documentation (including a PDF product brief) is to be believed (thanks to the Inquirer for the heads-up), the company is poised to unveil up-to-750 GByte Barracuda 7200.10 mainstream 7200 RPM PATA and SATA HDDs. Commentary comes courtesy of digg and Slashdot.

Why's there a capacity discrepency between the enterprise and consumer HDDs? Compare the RPM ratings. At a given read/write head technology generation, it's possible to pack more storage into a given-sized portion of a platter side when the platter is spinning more slowly. However, regardless of the drive's RPM rating, PMR enables denser bit-packing than traditional longitudinal techniques allow. There's also a sustained transfer rate performance benefit; at comparable RPMs, PMR drives can read or write more data in a given amount of time as compared to longitudinal counterparts.

Followup: it's here… (please use your best Poltergeist voice when reading the preceding text, which is appropriate given that Seagate refers to the new drive as a 'Monster')