Industry leader Seagate Technology has lagged competitors in releasing a high-capacity, SATA-based products intended for use in the more demanding nearline enterprise environment. Now, however, the company feels that various factors have combined to create a more practical enterprise SATA market. Seagate’s NL35 takes aim at the likes of Maxtor’s MaXLine and WD’s Caviar RE? How do its features and performance stack up? StorageReview examines!
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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:
Hitachi Deskstar 7K400 (400 GB) | Same-generation desktop unit |
Maxtor MaXLine III (300 GB) | Current-generation competing unit |
Samsung SpinPoint P80 (160 GB) | Previous-generation desktop unit |
Seagate Barracuda 7200.8 (400 GB) | Manufacturer’s current-generation desktop unit |
Western Digital Caviar RE2 WD4000YR (400 GB) | Current-generation competing unit |
Access Time and Transfer RateFor diagnostic purposes only, StorageReview measures the following low-level parameters: Average Read Access Time– An average of 25,000 random read accesses of a single sector each conducted through IPEAK SPT’s AnalyzeDisk suite. The high sample size permits a much more accurate reading than most typical benchmarks deliver and provides an excellent figure with which one may contrast the claimed access time (claimed seek time + the drive spindle speed’s average rotational latency) provided by manufacturers. Average Write Access Time– An average of 25,000 random write accesses of a single sector each conducted through IPEAK SPT’s AnalyzeDisk suite. The high sample size permits a much more accurate reading than most typical benchmarks deliver. Due to differences in read and write head technology, seeks involving writes generally take more time than read accesses. |
WB99 Disk/Read Transfer Rate – Begin– The sequential transfer rate attained by the outermost zones in the hard disk. The figure typically represents the highest sustained transfer rate a drive delivers.
WB99 Disk/Read Transfer Rate – End– The sequential transfer rate attained by the innermost zones in the hard disk. The figure typically represents the lowest sustained transfer rate a drive delivers.
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The NL35 turns in an average read access time of 13.1 milliseconds. Subtracting 4.2 ms to account for the rotational latency of a 7200 RPM spindle leaves the drive with a measured read seek time of 8.9 milliseconds. While this mark misses the manufacturer’s claim by nearly a full millisecond, it is interesting to note that the NL35’s score maintains a half-millisecond lead over the mechanically-similar Barracuda 7200.8. In fact, the gap between the two drives balloons with average write access times. The NL35’s write score weighs in at 15.2 ms; the Barracuda lags with a staggering 23.3 ms result.
With an outer-zone transfer rate of 71.9 MB/sec, the NL35 sets a new SATA transfer rate record. Speeds naturally decay as data moves towards the inner tracks with Seagate’s drive bottoming at 41.1 MB/sec. Both scores come in slightly higher than that of the NL35’s consumer-oriented brother. The overall shape of the two drives’ graphs remain quite similar to each other, but the NL35’s contour remains a bit cleaner- the various zones and drops in transfer rates are a bit more discrete than in the graph delivered by the Barracuda 7200.8.
Some Perspective It is important to remember that seek time and transfer rate measurements are mostly diagnostic in nature and not really measurements of “performance” per se. Assessing these two specs is quite similar to running a processor “benchmark” that confirms “yes, this processor really runs at 2.4 GHz and really does feature a 400 MHz FSB.” Many additional factors combine to yield aggregate high-level hard disk performance above and beyond these two easily measured yet largely irrelevant metrics. In the end, drives, like all other PC components, should be evaluated via application-level performance. Over the next few pages, this is exactly what we will do. Read on! |
Single-User PerformanceStorageReview uses the following tests to assess non-server use: StorageReview.com Office DriveMark 2006– A capture of VeriTest’s Business Winstone 2004 suite. Applications include Microsoft’s Office XP (Word, Excel, Access, Outlook, and Project), Internet Explorer 6.0, Symantec Antivirus 2002 and Winzip 9.0 executed in a lightly-multitasked manner. StorageReview.com High-End DriveMark 2006– A capture of VeriTest’s Multimedia Content Creation Winstone 2004 suite. Applications include Adobe Photoshop v7.01, Adobe Premiere v6.5, Macromedia Director MX v9.0, Macromedia Dreamweaver MX v6.1, Microsoft Windows Media Encoder 9.0, Newtek Lightwave 3D 7.5b, and Steinberg Wavelab 4.0f run in a lightly-multitasked manner. For more information, please click here. |
An SR Office DriveMark of 559 I/Os per second (with NCQ disabled) permits the Seagate NL35 to edge out the desktop-oriented Barracuda 7200.8 by a slim 3 IOps. In relative terms, this score places Seagate’s enterprise SATA unit a bit behind the speedsters delivered by the competition. It is interesting to note that, like the 7200.8, the NL35 suffers considerably in productivity performance with NCQ enabled. Its score plunges by 17% with this feature active.
The NL35 delivers an SR High-End DriveMark of 508 I/Os per second (NCQ enabled) and again leads the Barracuda by a 3 IOps cushion. The result allows the NL35 to climb a bit relative to other drives. Note that here, unlike with the Office test, NCQ’s presence benefits the NL35. Disabling NCQ results in a slide of about 3%.
Gaming PerformanceThree decidedly different entertainment titles cover gaming performance in StorageReview’s test suite. FarCry, a first-person shooter, remains infamous for its lengthy map loads when switching levels. The Sims 2, though often referred to as a “people simulator,” is in its heart a strategy game and spends considerable time accessing the disk when loading houses and lots. Finally, World of Warcraft represents the testbed’s role-playing entry; it issues disk accesses when switching continents/dungeons as well as when loading new textures into RAM on the fly. For more information, please click here. |
With NCQ active, the Seagate NL35 matches the Barracuda 7200.8’s FarCry performance at 629 I/Os per second.
The NL35 manages a slight lead over the Barracuda in the Sims2.
When running through our World of Warcraft trace, the NL35 for a change finds itself towards the upper-end of a very tightly-grouped cadre of drives.
Multi-User PerformanceUnlike single-user machines (whether a desktop or workstation), servers undergo highly random, non-localized access. StorageReview simulates these multi-user loads using IOMeter. The IOMeter File Server pattern balances a majority of reads and minority of writes spanning requests of varying sizes. IOMeter also facilitates user-configurable load levels by maintaining queue levels (outstanding I/Os) of a specified depth. Our tests start with the File Server pattern with a depth of 1 and double continuously until depth reaches 128 outstanding I/Os. Drives with any sort of command queuing abilities will always be tested with such features enabled. Unlike single-user patterns, multi-user loads always benefit when requests are reordered for more efficient retrieval. For more information click here. |
By virtue of its substantially lower random access time, the NL35 manages slightly better scores across the board when contrasted with the Barracuda in the IOMeter File Server suite. Under light to moderate loads with anywhere between 1 to 8 I/Os outstanding, the NL35 lags the competition a bit. As depths get heavier, however, the NL35 levels off more rapidly, leaving a substantial gap between itself and other units in delivered IOps.
These results may be related to each drive’s relative target market. Western Digital’s Caviar WD4000YR, for example, represents the company’s entry into capacity-oriented arrays is rated and positioned for a full-bore 100% duty cycle. Seagate’s drive, on the other hand, targets the nearline sector almost exclusively and leaves more demanding tasks to drives such as the firm’s own workhorse Cheetah 10K series.
Noise and Power MeasurementsIdle Noise– The sound pressure emitted from a drive measured at a distance of 3 millimeters. The close-field measurement allows for increased resolution between drive sound pressures and eliminates interactions from outside environmental noise. Note that while the measurement is an A-weighted decibel score that weighs frequencies in proportion to human ear sensitivity, a low score does not necessarily predict whether or not a drive will exhibit a high-pitch whine that some may find intrusive. Conversely, a high score does not necessarily indicate that the drive exhibits an intrusive noise profile. Operating Power Dissipation– The power consumed by a drive, measured both while idle and when performing fully random seeks. In the relatively closed environment of a computer case, power dissipation correlates highly with drive temperature. The greater a drive’s power draw, the more significant its effect on the chassis’ internal temperature. |
Startup (Peak) Power Dissipation– The maximum power dissipated by a drive upon initial spin-up. This figure is relevant when a system features a large number of drives. Though most controllers feature logic that can stagger the spin-up of individual drives, peak power dissipation may nonetheless be of concern in very large arrays or in cases where a staggered start is not feasible. Generally speaking, drives hit peak power draw at different times on the 5V and 12V rails. The 12V peak usually occurs in the midst of initial spin-up. The 5V rail, however, usually hits maximum upon actuator initialization.
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The NL35 delivers an objectively-measured sound pressure of 42.7 dB/A. Despite the slight gap, however, the drive’s overall noise profile remains quite similar to that of the Barracuda 7200.8. Idle noise is barely audible when outside a case. Seeks are quite muted and among the quietest available from today’s 7200 RPM drives.
Despite their similarities, the NL35 manages a slightly more friendly power profile than the 7200.8. At idle, the NL35 consumes 7.9 watts, just over half a watt less than the Barracuda. This margin maintains itself under full-seek conditions. The NL35’s 11.5 watt score again remains about half a watt lighter than the 7200.8. Compared to the competition, Seagate’s drive fares well. Featuring a three-platter design thanks to its high density, the NL35 dissipates less power than four- and five-platter competing designs and as a result operates cooler.
Though attenuated just a hair, the NL35 shares the Barracuda 7200.8’s curiously-high peak power draw. A power-on draw of 30+ watts places the NL35 well into the territory occupied by today’s 10K and 15K RPM drives.
ReliabilityThe StorageReview.com Reliability Survey aims to amalgamate individual reader experiences with various hard disks into a comprehensive warehouse of information from which meaningful results may be extracted. A multiple-layer filter sifts through collected data, silently omitting questionable results or results from questionable participants. A proprietary analysis engine then processes the qualified dataset. SR presents results to readers through a percentile ranking system. According to filtered and analyzed data collected from participating StorageReview.com readers, the |
According to filtered and analyzed data collected from participating StorageReview.com readers, a predecessor of the
Seagate NL35, the
Seagate Barracuda 7200.7
, is more reliable than of the other drives in the survey that meet a certain minimum floor of participation.
Note that the percentages in bold above may change as more information continues to be collected and analyzed. For more information, to input your experience with these and/or other drives, and to view comprehensive results, please visit the SR Drive Reliability Survey.
ConclusionIn the end, the Seagate NL35’s performance delivers few surprises. Incorporating most of the basic physical technology found in the Barracuda 7200.8, the NL35’s performance in both single-user and multi-user environments closely mirrors that of the Barracuda, with the former enjoying a slight advantage across the board likely due to its better write access time. Such performance admittedly leaves the NL35 at odds with the Maxtor MaXLine III and Western Digital’s Caviar RE2, both of which are derived from the firms’ respective high-performance SATA designs. Lately, however, Seagate’s enterprise arm has been deemphasizing the importance of sheer performance in favor of leveraging the firm’s leading reliability (as backed up by StorageReview’s own Reliability Survey) into a diverse and specialized product line. Seagate argues that while the NL35 does not match the raw speed of the competition, the drive nonetheless delivers the reliability and feature set necessary for nearline applications. |
Our look at Seagate’s nearline offering does not end here. As an enterprise-oriented design, the NL35 will undergo Testbed4’s expanded multi-drive performance treatment. Stay tuned for more results!
