Seagate NL35

Seagate NL35 Available Capacities Model Number Capacity ST3250832NS 250 GB ST3400832NS 400 GB Lowest Real-Time Price (400 GB): Introduction The storage world is changing. In the past, in IT's relative infancy, it sufficed to have all readily-needed data stored on performance-oriented, enterprise-class SCSI disks while archiving older data onto the low cost (but, due to linear access, extremely slow) tape backup systems. As time has passed, however, two factors have exponentially driven the need for greater random-access storage.

First, data itself grew larger and more expansive as hardware and software advanced. Second, there simply became more and more to archive. Back in the 1990's, there was only so much of an electronic "paper trail" of sorts to backup. Today, however, firms are potentially looking at years and even decades worth of information. As this data ages and/or becomes less relevant, the need for constant access fades more rapidly than the need for infrequent yet immediate retrieval.

Storing such data on a linearly-accessed, "offline" system such as tape instead of random-access devices like disks saves money... until that data is needed, after which the labor and time invested in the retrieval process may shatter this sense of false economy. On the flip side, however, as large as today's enterprise-class drives are, the use of "online" 15K RPM or even 10K RPM drives to store many terabytes of infrequently accessed information can mount formidable costs of its own.

Storage manufacturers have tackled the issue by introducing a new class of device, the "nearline" drive that, when combined with the aforementioned online and offline segments, tiers today's enterprise storage into three distinct levels. By keeping highly-accessed, current information in the traditional domain of high-speed, swift-actuator drives and relegating less-used but still-accessed data to slower, less expensive devices, drive firms aspire to deliver solutions that balance the needs for performance with cost.

A manufacturer's basic approach involves taking a tried-and-true desktop-oriented ATA design and retooling the manufacturing and testing process to qualify the product for the more demanding enterprise environment. Industry giant Seagate is a relative latecomer to the nearline segment. While competitors Maxtor and Western Digital forged ahead with their MaXLine and Caviar RE families, Seagate chose to wait until the parallel ATA paradigm segued into the more appropriate SATA standard. SATA's interoperability with the impending Serial Attached SCSI (SAS) standard clears the way to a seamless integration of two formerly discrete standards and infrastructures. With SATA's maturation and SAS's impending arrival, Seagate finally believes the time is right to enter the nearline sector.

Its NL35 leverages the design of the firm's current SATA mainstay, the Barracuda 7200.8. The specs read quite similarly: 7200 RPM spindle speed, 8 millisecond seek time, an 8-megabyte buffer, and three 133 GB platters to yield a 400 GB capacity. The Barracuda family was the first to incorporate Native Command Queuing (NCQ); the NL35 maintains this feature, especially important in the multi-user enterprise space. A five-year warranty protects the drive.

A few key changes differentiate the NL35 from its desktop-oriented cousin. First, the manufacturing and validation process have been modified to bump up the drive's mean time between failures to one million hours under nearline loads. Further, a trio of features make the NL35 more appropriate for the nearline space. "Error Recovery Control" permits array administrators to better coordinate the drive's internal error recovery system with that of a RAID controller. When loads exceed the drive's intended design, "Workload Management" introduces a read after every write and effects a dual solution of slowing down (and thus preserving) the drive as well as verifying the written data. Finally, a one-step microcode download feature ensures minimal downtime by allowing administrators to flash the firmware of all drives on the array simultaneously as opposed to one at a time.

As capacious, nearline-oriented drive leveraged from a 7200 RPM SATA design, the Seagate NL35 will be compared against these drives in the tests that follow: