Product segmentation is a delicate art that tech companies have come to master. We see it in the semiconductor industry, where chip makers derive a range of products from the same base silicon. Clock speeds are tweaked, functional units are trimmed, and switches are flipped to remove certain features.
The same sort of thing happens in the storage world. Drive platters are shared between hybrid SSHDs, high-performance 7,200-RPM hard drives, and low-power models with slower spindle speeds. Some drives are tuned for typical client workloads, while others are optimized for RAID implementations and network-attached storage.
Seagate’s lineup is perhaps the best example of this kind of segmentation in action. The same 1TB platters can be found in the Desktop SSHD 2TB, the 7,200-RPM Barracuda 3TB, and the 5,900-RPM Desktop HDD.15. The Desktop HDD.15 is meant for desktop systems, and it has a NAS-centric twin geared toward external storage arrays and internal RAID configs.
On the surface, the NAS HDD 4TB looks identical to its Desktop HDD.15 sibling. Were it not for the labels, you’d have a hard time telling the two apart.
The mix of components on the associated circuit boards is different—but only slightly. You’re basically looking at two versions of the same drive. The thing is, the NAS HDD sells for $220, while the Desktop HDD.15 rings in at only $170. What gives?
A few things, actually. The NAS HDD is covered by a three-year warranty, while the Desktop HDD.15’s coverage runs out after only two years. Longer warranty coverage doesn’t necessarily translate to better reliability, of course, but the accompanying specifications suggest the NAS HDD is more robust than its desktop counterpart. The NAS drive is rated for twice as many load/unload cycles and more than three times the number of power-on hours as the desktop model. It’s also certified for 24×7 operation, a blessing not bestowed upon the Desktop HDD.15.
Next on the list: validation testing for a wide range of network-attached storage devices. The NAS HDD offers guaranteed compatibility with scores of different NAS boxes from 10 different device providers. The drive is only qualified for devices with up to five bays, though. Seagate has enterprise-oriented models with additional features targeting servers and storage devices with more bays.
The “NASWorks” umbrella covers the rest of the NAS HDD’s unique attributes. This marketing term encompasses a number of capabilities, including vibration minimization, power management, and error recovery.
All mechanical hard drives vibrate to some extent. That’s usually not a problem for well-anchored drives in desktop systems. However, vibration can compromise performance and reliability when multiple drives are tightly packed into the small enclosures typical of NAS boxes. In the NAS HDD, “dual-plane balance” tech aims to reduce vibration by “better balancing the drive motor.” Seagate also says the drive has “better components for vibration tolerance” than the Desktop HDD.15.
On the power management front, the NAS HDD is governed by custom rules about when to engage sleep and standby modes. NAS devices can have different expectations than desktop systems about how readily data should be accessible. NASWorks takes those preferences into account while still pursuing low-power states.
NAS devices also have different expectations surrounding error recovery, a trait they share with desktop RAID configurations. If a drive spends too long chasing down an error, it can be marked as bad or unresponsive and dropped from the array. Even if the drive is undamaged, rebuilding the array can be time consuming, and performance will almost certainly be compromised until the rebuild is complete. NASWorks includes time-limited error recovery to prevent premature disconnects, leaving the NAS device or RAID controller to pick up after any error recovery attempts that are cut short.
Support for the ATA Streaming command set isn’t explicitly tied to NASWorks, but it might as well be. This optional component of the ATA specification allows hosts to demand data on a specific timeline. ATA Streaming commands are used by some consumer electronics devices, and as far as I can tell, they’re not supported by the Desktop HDD.15. The other NASWorks perks I’ve mentioned aren’t available on the desktop drive, either.
|Spindle speed||5,900 RPM|
|Max sustained data rate||180MB/s|
|Average read/write seek time||< 12 ms|
|Typical idle power||3.95W|
|Typical seek power||4.8W|
|Idle acoustics||2.3 bels|
|Operating acoustics||2.5 bels|
|Warranty length||Three years|
Seagate says the NAS HDD’s firmware has been tuned to balance sequential and random performance. The drive’s maximum sustained data rate matches that of the Desktop HDD.15. However, the desktop drive has quicker average seek times: less than 8.5 ms for reads and under 9.5 ms for writes, both notable improvements over the sub-12-ms figure quoted for the NAS HDD. We’ll get to our own performance tests in a moment, but first, I have a bone to pick.
Apparently following WD’s IntelliPower example, Seagate appears to be obfuscating the NAS HDD’s spindle speed. The rotational speed isn’t referenced anywhere in the product documentation, so we had to ask Seagate for clarification. The manual does quote the drive’s average latency as 5.1 milliseconds, which matches the latency of the 5,900-RPM Desktop HDD.15, so there’s at least enough information to work backward to an answer.
Although I get that consumers don’t need to be inundated with numbers they may not understand (and that may be somewhat less relevant for low-power offerings that don’t focus on performance), it’s silly that drive makers have become hesitant to reveal such a defining specification in their datasheets. Only nerds look at those documents, and making us extrapolate the spindle speed from the rotational latency seems unnecessary.
Anyway, enough with that tangent. Let’s move on to our performance results.
Lining up the competition
Over the following pages, we’ll compare the NAS HDD 4TB’s performance to that of a diverse collection of mechanical drives. You’ll want to pay particular attention to how the NAS drive stacks up against the Desktop HDD.15. Also, keep your eye on the Red 4TB, which is WD’s entry into the NAS-friendly market.
|Interface||Cache||Spindle speed||Areal density|
|Hitachi Deskstar 7K3000 3TB||6Gbps||64MB||7,200 RPM||411 Gb/in²|
|Seagate Barracuda 3TB||6Gbps||64MB||7,200 RPM||625 Gb/in²|
|Seagate Desktop HDD.15 4TB||6Gbps||64MB||5,900 RPM||625 Gb/in²|
|Seagate Desktop SSHD 2TB||6Gbps||64MB||7,200 RPM||625 Gb/in²|
|Seagate NAS HDD 4TB||6Gbps||64MB||5,900 RPM||625 Gb/in²|
|WD Caviar Black 1TB||6Gbps||64MB||7,200 RPM||400 Gb/in²|
|WD Caviar Black 2TB||6Gbps||64MB||7,200 RPM||400 Gb/in²|
|WD Black 4TB||6Gbps||64MB||7,200 RPM||NA|
|WD Red 3TB||6Gbps||64MB||5,400 RPM||NA|
|WD Red 4TB||6Gbps||64MB||5,400 RPM||NA|
|WD VelociRaptor VR200M 600GB||6Gbps||32MB||10,000 RPM||NA|
|WD VelociRaptor 1TB||6Gbps||64MB||10,000 RPM||NA|
Although the NAS HDD doesn’t compete directly with SSDs, we couldn’t resist including a batch of the latest solid-state drives in the mix. The results from these drives will provide some valuable perspective on the performance differences between the NAS HDD and its mechanical peers.
|Crucial M500 240GB||256MB||Marvell 88SS9187||20nm Micron sync MLC|
|Intel 335 Series 240GB||NA||SandForce SF-2281||20nm Intel sync MLC|
|OCZ Vector 256GB||512MB||Indilinx Barefoot 3||25nm Intel sync MLC|
|Samsung 840 Series 250GB||512MB||Samsung MDX||21nm Samsung Toggle TLC|
|Samsung 840 Pro 256GB||512MB||Samsung MDX||21nm Samsung Toggle MLC|
|Seagate 600 SSD 240GB||256MB||LAMD LM87800||19nm Toshiba Toggle MLC|
These six drives nicely cover some of the more popular controller and NAND combinations for modern SSDs. We have representatives from the high end of the spectrum, the more affordable side, and multiple points in between. All the drives are in the 240-256GB range.
If you’re a TR regular already familiar with our storage test system and methods, feel free to skip ahead to the performance results. Apart from minor tweaks to the table below, the rest of this page is copied lazily from previous reviews. But I’ve added one more money shot of the NAS HDD as a bonus. Thanks for not skipping to the conclusion!
Our test methods
We used the following system configuration for testing:
|Processor||Intel Core i5-2500K 3.3GHz|
|CPU cooler||Thermaltake Frio|
|Motherboard||Asus P8P67 Deluxe|
|Platform hub||Intel P67 Express|
|Platform drivers||INF update 188.8.131.520
|Memory size||8GB (2 DIMMs)|
|Memory type||Corsair Vengeance DDR3 SDRAM at 1333MHz|
|Audio||Realtek ALC892 with 2.62 drivers|
|Graphics||Asus EAH6670/DIS/1GD5 1GB with Catalyst 11.7 drivers|
|Hard drives||Crucial M500 256GB with MU02 firmware
Intel 335 Series 240GB with 335s firmware
OCZ Vector 256GB with 10200000 firmware
Samsung 840 Series 250GB with DXT07B0Q firmware
Samsung 840 Pro Series 256GB with DXM04B0Q firmware
Hitachi Deskstar 7K3000 3TB with MKA0A580 firmware
Seagate Barracuda 3TB with CC47 firmware
Seagate Desktop HDD.15 4TB with B660 firmware
Seagate 600 SSD with B660 firmware
Seagate NAS HDD 4TB with SC43 firmware
Seagate Desktop SSHD 2TB with CC43 firmware
WD Caviar Black 1TB with 05.01D05 firmware
WD Caviar Black 2TB with 01.00101 firmware
WD Red 3TB with 80.00A80 firmware
WD Red 4TB with 80.00A80 firmware
WD VelociRaptor VR200M 600GB with 04.05G04 firmware
WD VelociRaptor 1TB with 04.06A00 firmware
WD Black 4TB with 01.01L01 firmware
|Power supply||Corsair Professional Series Gold AX650W|
|OS||Windows 7 Ultimate x64|
Thanks to Asus for providing the systems’ motherboards and graphics cards, Intel for the CPUs, Corsair for the memory and PSUs, Thermaltake for the CPU coolers, and Western Digital for the Caviar Black 1TB system drives.
We used the following versions of our test applications:
- Intel IOMeter 1.1.0 RC1
- HD Tune 4.61
- TR DriveBench 1.0
- TR DriveBench 2.0
- TR FileBench 0.2
- Qt SDK 2010.05
- MiniGW GCC 4.4.0
- Duke Nukem Forever
- Portal 2
Some further notes on our test methods:
- To ensure consistent and repeatable results, the SSDs were secure-erased before almost every component of our test suite. Some of our tests then put the SSDs into a used state before the workload begins, which better exposes each drive’s long-term performance characteristics. In other tests, like DriveBench and FileBench, we induce a used state before testing. In all cases, the SSDs were in the same state before each test, ensuring an even playing field. The performance of mechanical hard drives is much more consistent between factory fresh and used states, so we skipped wiping the HDDs before each test—mechanical drives take forever to secure erase.
- We run all our tests at least three times and report the median of the results. We’ve found IOMeter performance can fall off with SSDs after the first couple of runs, so we use five runs for solid-state drives and throw out the first two.
- Steps have been taken to ensure that Sandy Bridge’s power-saving features don’t taint any of our results. All of the CPU’s low-power states have been disabled, effectively pegging the 2500K at 3.3GHz. Transitioning in and out of different power states can affect the performance of storage benchmarks, especially when dealing with short burst transfers.
The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at a 75Hz screen refresh rate. Most of the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.
The acoustic footprint of a hard drive has become one of its most important attributes—especially for PC enthusiasts who have built themselves near-silent systems. We’re a little OCD here at TR, so we’ve constructed a Box ‘o Silence to test the noise emitted by mechanical hard drives. This 18″ x 20″ anechoic chamber is lined with acoustic foam, and we suspend hard drives inside it, exactly 4″ away from the tip of our TES-52 digital sound level meter. You can read more about the setup here.
To ensure the lowest possible ambient noise levels, we swapped the test system’s graphics card for a passively cooled Gigabyte card and unplugged one of the Frio CPU cooler’s dual fans. Noise levels were measured after one minute of idling at the Windows desktop and during an HD Tune seek test.
We’ve color-coded the results by manufacturer to make the graphs easier to read. Because they have no moving parts and are essentially silent, the SSDs are missing from the noise results. When they do appear in the graphs, the corresponding bars are greyed out to set apart what is really a different class of PC storage.
Although the NAS HDD is nearly as quiet as the Desktop HDD.15 at idle, it’s much louder when seeking. In both cases, the WD Red 4TB is noticeably quieter. In fact, the WD drive makes less noise while seeking than the NAS HDD does at idle. You can definitely hear the difference between the two.
The NAS HDD’s noise levels actually spiked as high as 38 decibels during our testing, likely due to excessive vibration. Our suspension system relies on elastic cords that hum audibly when the NAS HDD is hanging in the Box ‘o Silence. The Desktop HDD.15 behaved similarly, so we used the same trick we employed to dampen that model’s vibration. A paperback book was placed on top of the drive during our noise testing, adding enough weight to tension the suspension cords and reduce their oscillation. This approach eliminated chirping on the Desktop HDD.15, but it didn’t eradicate the blips entirely on the NAS HDD.
Adding our paperback (Zen and the Art of Motorcycle Maintenance, if you’re curious) only appears to affect vibration-induced noise. We tested the WD Black 4TB with and without the book in place, and that drive’s noise levels were unchanged. I’m already contemplating a new mounting system for the Box ‘o Silence—and a test to measure drive vibration.
Power consumption was tested under load with IOMeter’s workstation access pattern chewing through 32 concurrent I/O requests. Idle power consumption was probed one minute after processing Windows 7’s idle tasks on an empty desktop.
The NAS HDD’s power consumption is identical to that of its desktop counterpart. The Red 4TB is more power-efficient at idle, but it draws more power under load. I wouldn’t worry too much about such small gaps, though. Even if you multiply the deltas to account for five-drive arrays, the differences won’t have a big impact on your monthly utility bill.
Our real-world load time tests show how the NAS HDD handles typical desktop scenarios. Before timing a couple of applications, we first have to load the OS. We can measure how long that takes by checking the Windows 7 boot duration using the operating system’s performance-monitoring tools.
Level load times
The NAS HDD is up to a second slower than the Desktop HDD.15, putting it firmly at the back of the field. Seagate’s NAS offering loads the OS a couple of seconds slower than the Red 4TB, and it’s behind the WD drive by similar margins in the gaming tests.
These results nicely illustrate why you want your OS and applications on an SSD instead of a hard drive. Even the slowest SSDs load Windows and our game levels much faster than the mechanical drives, though Seagate’s Desktop SSHD hybrid does an admirable job of closing the gap between the two classes of PC storage.
HD Tune — Transfer rates
HD Tune lets us look at transfer rates across the extent of the drive, and we’ve plotted the full profiles for the mechanical drives in the line graphs below. The SSDs are fast enough to throw off the scale, so we’ve left them out. You can click the buttons below each of the line graphs to see how the NAS HDD compares to different classes of competitors.
HD Tune’s sequential transfer rate tests run a little bit faster on the NAS HDD than they do on the Desktop HDD.15. The differences amount to only 5MB/s, but they’re pretty consistent across the extent of the drive.
Although the NAS HDD trails its desktop twin, the drive still beats the Red 4TB handily. The differences there are much greater: 15-16MB/s.
This next test measures the speed of short “burst” transfers that target the DRAM caches on traditional hard drives.
The NAS HDD turns the tables on the Desktop HDD.15, posting slightly higher burst rates in both HD Tune tests. Those two drives have much slower burst rates than Seagate’s own Barracuda 3TB, though. They’re also well behind the WD Red 4TB.
HD Tune — Random access times
Our next set of HD Tune tests probes random access times with various transfer sizes. We’ll start with a line graph showing all the results before moving onto bar charts that cover a couple of key transfer sizes. You can click the buttons below the graph to see how the NAS HDD compares to different classes of rivals.
There’s something funky going on with the NAS HDD’s 512-byte read access times, and it’s probably related to the drive’s use of native 4KB sectors. Unfortunately, the NAS HDD’s 4KB read access times are among the slowest we’ve ever measured. At least the NAS HDD’s 1MB read access times are relatively snappy—and quicker than those of the Desktop HDD.15 and Red 4TB.
More weirdness is evident in our random write results, and again, it’s mostly confined to the 512-byte test. This time around, the Desktop HDD.15 looks like the outlier. Its 4KB random write access times are much slower than those of the NAS HDD, though the desktop model has a slight edge in the 1MB test. The Red 4TB has quicker access times than its Seagate rival across the board.
I’d be remiss if I didn’t point out the fact that the SSDs are at times multiple orders of magnitude quicker than the mechanical drives in these tests. Unless you’ve had your head in the sand for the past few years, you probably knew that already.
TR FileBench — Real-world copy speeds
Concocted by resident developer Bruno “morphine” Ferreira, FileBench runs through a series of file copy operations using Windows 7’s xcopy command. Using xcopy produces nearly identical copy speeds to dragging and dropping files using the Windows GUI, so our results should be representative of typical real-world performance. We tested using the following five file sets—note the differences in average file sizes and their compressibility. We evaluated the compressibility of each file set by comparing its size before and after being run through 7-Zip’s “ultra” compression scheme.
|Number of files||Average file size||Total size||Compressibility|
The names of most of the file sets are self-explanatory. The Mozilla set is made up of all the files necessary to compile the browser, while the TR set includes years worth of the images, HTML files, and spreadsheets behind my reviews. Those two sets contain much larger numbers of smaller files than the other three. They’re also the most amenable to compression.
The SSDs were tested in a simulated used state that should be representative of their long-term performance. We didn’t simulate a used state with the mechanical drives or hybrids, which tend to offer consistent performance regardless of whether we’ve run our used-state torture test.
The NAS HDD ties with the Red 4TB in one of our FileBench tests, but it’s behind in all the others. The gap between those two NAS-specific drives is particularly apparent in the Mozilla and TR tests, which are made up of large numbers of small files.
Versus its desktop sibling, the NAS HDD consistently pulls up short. The two drives stick close together in the Mozilla and TR tests, but the gap between them widens when the drives are copying the larger files in the other tests.
TR DriveBench 1.0 — Disk-intensive multitasking
TR DriveBench allows us to record the individual IO requests associated with a Windows session and then play those results back as fast as possible on different drives. We’ve used this app to create a set of multitasking workloads that combine common desktop tasks with disk-intensive background operations like compiling code, copying files, downloading via BitTorrent, transcoding video, and scanning for viruses. The individual workloads are explained in more detail here.
Below, you’ll find an overall average followed by scores for each of our individual workloads. The overall score is an average of the mean performance score for each multitasking workload.
Our first wave of DriveBench tests pushes the NAS HDD to the back of the field, where it trails the Desktop HDD.15 and falls well behind the Red 4TB. Do the individual test results provide any relief?
Not really. The NAS HDD claws out of last place in a couple of tests, but it’s consistently beaten by the Red 4TB. With the exception of the file copy test, where the Desktop HDD.15 struggles mightily, the 4TB Seagate drives are closely matched.
TR DriveBench 2.0 — More disk-intensive multitasking
As much as we like DriveBench 1.0’s individual workloads, the traces cover only slices of disk activity. Because we fire the recorded I/Os at the disks as fast as possible, solid-state drives also have no downtime during which to engage background garbage collection or other optimization algorithms. DriveBench 2.0 addresses both of those issues with a much larger trace that spans two weeks of typical desktop activity peppered with multitasking loads similar to those in DriveBench 1.0. We’ve also adjusted our testing methods to give solid-state drives enough idle time to tidy up after themselves. More details on DriveBench 2.0 are available on this page of our last major SSD round-up.
Instead of looking at a raw IOps rate, we’re going to switch gears and explore service times—the amount of time it takes drives to complete an I/O request. We’ll start with an overall mean service time before slicing and dicing the results.
Well, that doesn’t bode well. The Desktop HDD.15 scores poorly in DriveBench 2.0 overall, and the NAS HDD fares even worse.
Let’s slice and dice the data with a few more metrics. We’ll start by splitting mean service times between read and write requests.
The NAS HDD struggles more with reads than it does with writes. In both categories, its mean service times are slower than those of the Desktop HDD.15. They’re also slower than the access times of the Red 4TB.
There are tens of millions of I/O requests in this trace, so we can’t easily graph all the service times to look at the variance. However, our analysis tools do report the standard deviation, which can give us a sense of how much service times vary from the mean.
Again, the NAS HDD finds itself at the back of the pack. Its write service times are much less consistent than those of the Red 4TB. The two NAS-oriented models have similar variance in their read service times, though.
We can’t easily graph all the service times recorded by DriveBench 2.0, but we can sort them. The graphs below plot the percentage of service times that fall below various thresholds. You can click the buttons below the graphs to see how the NAS HDD compares to different classes of mechanical and solid-state drives.
The distribution plots nicely highlight how closely the NAS HDD and Desktop HDD.15 match up. The Red 4TB has more service times under each threshold, giving the WD drive a clean sweep.
All the lines converge when we hit the 100-millisecond threshold on the far right. Service times beyond that point may be long enough for end users to perceive, but it’s hard to tell the drives apart from this perspective. That’s why we’ve busted out another set of graphs that shows the percentages of service times over 100 ms for each drive. The percentages are low overall, but keep in mind that we’re dealing with tens of millions of I/O requests logged over nearly two weeks of desktop activity.
Well, there’s no salvation for the NAS HDD here. The drive fares slightly better than the Desktop HDD.15 with reads but a little worse with writes. The Red 4TB has fewer extremely long read service times than its similarly sized Seagate rivals and less than half the number of write service times over 100 ms.
Our IOMeter workloads feature a ramping number of concurrent I/O requests. Most desktop systems will only have a few requests in flight at any given time (87% of DriveBench 2.0 requests have a queue depth of four or less). We’ve extended our scaling up to 32 concurrent requests to reach the depth of the Native Command Queuing pipeline associated with the Serial ATA specification. Ramping up the number of requests also gives us a sense of how the drives might perform in more demanding enterprise environments.
There’s too much data to easily show on a single graph for each access pattern, so we’ve once again split the results by drive class. You can compare the NAS HDD’s performance to that of the competition by clicking the buttons below each graph. Note that the scale is different for the Raptor results.
We’ve also banished the SSDs from this set of results. Their transaction rates demand a much higher scale, making it impossible to discern what’s going on with the mechanical drives. You can see how the SSDs compare on this page of our Samsung 840 EVO review.
Noticing a familiar theme yet? The Red 4TB delivers higher transaction rates than the NAS HDD throughout our IOMeter testing. Seagate’s NAS-specific drive largely matches the performance of its desktop twin, which is only good enough to pull even with the lower-capacity Red 3TB.
Of course, if you’re concerned with performance, you’re better off with a 7,200-RPM drive like the WD Black 4TB, which has a huge lead over its low-power peers throughout. Or, you know, get an SSD.
The value perspective
Welcome to our famous value analysis, which adds capacity and pricing to the performance data we’ve explored over the preceding pages. We used Newegg to price all of the drives, and we didn’t take mail-in rebates into account when performing our calculations.
First, we’ll look at the all-important cost per gigabyte, which we’ve obtained using the amount of storage capacity accessible to users in Windows.
Although the NAS HDD’s street price is higher than that of the Desktop HDD.15, it’s comparable to the going rate for the Red 4TB. The premium associated with the NAS-specific models works out to only about a penny per gigabyte, at least versus standard desktop drives.
The SSDs cost a lot more per gig, of course. That’s why it’s best to combine solid-state and mechanical storage in desktop systems. The SSD can provide just enough wicked-fast storage for your OS and applications, while the hard drive stores media files and other data that doesn’t need to be accessed as quickly.
Our remaining value calculation uses a single performance score that we’ve derived by comparing how each drive stacks up against a common baseline provided by the Momentus 5400.4, a 2.5″ notebook drive with a 5,400-RPM spindle speed. This index uses a subset of our performance data described on this page of our last SSD round-up.
If you’ve been following along, this result shouldn’t come as a surprise. The NAS HDD 4TB is one of the slowest 3.5″ drives we’ve tested. At least it scores better than the Desktop HDD.15 in our overall metric, but that small victory is largely overshadowed by the Red 4TB’s higher score.
Now for the real magic. We can plot this overall score on one axis and each drive’s cost per gigabyte on the other to create a scatter plot of performance per dollar per gigabyte. The best place on the plot is the upper-left corner, which combines high performance with a low price. We’ll focus on the hybrids and mechanical drives first.
Our scatter plot doesn’t do the NAS HDD any favors. It nicely highlights the fact that the Red 4TB delivers higher overall performance at a slightly lower price.
We cropped out the VelociRaptors and SSDs to make the plot easier to read, but here’s a look at the landscape with all the drives included. Forgive the lack of labels for most of the mechanical drives—there’s no way to squeeze them in without making a mess.
We’re not interested in the difference between the mechanical drives, anyway. Instead, this plot is meant to illustrate the vast gulf between the solid-state and mechanical drives. The two classes of PC storage are far apart on both performance and price, which is why dual-drive solutions have become so popular among enthusiasts.
Hard drive makers have been repurposing platters to serve different markets for as long as I can remember. NAS-specific consumer drives are relatively new additions, though. A couple of years ago, this particular class of low-power mechanical drive didn’t really exist.
Given the lay of the storage landscape, adding NAS- and RAID-specific features to low-power consumer drives makes perfect sense. Network-attached storage devices are becoming increasingly popular with consumers seeking to share loads of data easily among multiple devices. In fact, the NAS market has heated up so much that drive makers are now offering their own boxes in addition to the drives that go inside.
On the desktop, NAS-optimized drives provide time-limited error recovery that should make PC RAID configurations more robust. SSDs have the market for high-performance storage pretty much sewn up, making speed less important for secondary storage. Low-power drives like the NAS HDD may be slower than 7,200-RPM mechanical models, but they’re also much quieter—an arguably more important characteristic for modern desktops.
Seagate’s NAS HDD ticks all the right boxes for this new breed of drive. It has RAID-friendly error recovery, NAS validation testing, and a handful of other little tweaks for its target environments. According to Seagate’s specifications, the NAS HDD should also be more reliable than its desktop counterpart, the HDD.15. There’s even an extra year of warranty coverage to provide additional peace of mind.
If this were merely a contest between the NAS HDD and its desktop twin, I could make a case for the $50 price difference between the two. There are rational reasons to pay $220 for the NAS HDD. There’s just one problem: the WD Red 4TB costs only $210 right now, and it’s the better of the two options. In addition to having similar NAS-specific goodness to its Seagate rival, the Red is faster overall. More importantly, it’s quieter—and noticeably so.
Given the competition, it’s difficult to recommend the NAS HDD 4TB. This class of hard drive will surely become more important in the coming years, but right now, the NAS HDD has some ground to make up on its primary competition.