Review: Western Digital My Book 6Tb USB 3.0 External Hard Drive

One thing power users know is that their appetite for storage is pretty much insatiable. In order to try satisfying this craving, I’ve decided to go on an all-out spending spree and grab myself some more storage. Instead of buying just any drive, I’ve decided to fork out for the largest consumer PMR drive on the market – i.e. a 6TB, rather than the more specialized SMR archive drive reviewed earlier which comes with write performance caveats, or the exotic and pricey helium filled Helioseal drives.

This comes at about a 22% premium per gigabyte over that of the best value (3Tb) drives, but since ports, space and energy can be the scarce commodity, it sometimes makes sense to fork out more for larger drives. Sometimes you’re working with very large files and you have no other option.

After doing some shopping around, it seemed that the only easily available drives in Australia were the Western Digital drives. As a result, I settled on four Western Digital My Book 6Tb drives at a cost of around AU$320 each delivered – a price cheaper than you would pay for the internal bare drives. A side benefit, when you’re getting them shipped, is the added protection the retail packaging and physical construction provides.

Unboxing

The product is packaged in a matte finish, colour print cardboard box, featuring a gradient blue finish with images of the drive prominently placed on both sides. The packaging seems to be a consumer-focused design with very little in the way of details, and only some mention of functionality that isn’t really part of the drive’s repertoire and more about the bundled third party software.

Only the top panel has information about the drive, which is placed in small text. The drive is a USB 3.0 device and comes pre-formatted in NTFS for compatibility with Windows machines, and requires reformatting for Mac OS. The package includes the drive, software (pre-loaded), USB cable, power adapter and quick install guide. Interestingly, this drive comes with a three year warranty for Asia Pacific Region, which is one year more than a bare WD Green drive sold in Australia which only has two years.

A quick start pictorial is provided on one side of the box, with some key features placed on the other. It’s interesting that they’ve been touting their security, as recent research seems to show that there are design flaws with some of Western Digital’s other USB based products. Not that these features are often used by end users, but it seems the Passport series of drives have a habit of encrypting everything anyway and making people’s lives hell when it comes to data recovery. The My Book series seems to be immune to this, at least, for now.

The drive itself is mostly a shiny black fingerprint-attracting finish, and is designed to stand vertically, as a book in a bookshelf might. The design, however, has curved sides and front, making it impossible to stack flat horizontally. This is probably done on purpose, to avoid overheating from packing too many drives together into a block, as it enforces some air space between vertically aligned units as well, but also means that the drive enforces a vertical orientation which may make it prone to accidental toppling which could cause severe drive damage. A small “cut-out” section is used to bring attention to the branding in a subtle way, but also exposes the small slit for a light-pipe where the activity LED indication is provided.

The drive, like most other Western Digital external drives, is generously vented from all sides. This unit uses the USB 3.0 microB connector, although on a few of my drives, it seems the connector shell was made a little too tight, making plugging the cable in difficult. A standard 2.5mm barrel connector is used for 12v DC input, with 5v provided by internal converter (thus eliminating a source of drive failure – switched 5v and 12v rails) as is standard with most modern external drives. A Kensington lock slot is also provided for security purposes. The drive itself feels fairly weighty, and no doubt because it is a six platter drive with 12 heads, pushing the envelope of what is reasonable in a 3.5″ drive.

The underside features relatively tall rubber feet, and a label indicating the model and serial number of the unit (blacked out above).

As promised, the drive is bundled with a quick-start guide, a warranty guide, K-tec 12v 1.5A power supply (as opposed to Asian Power Devices supplies formerly used) and the USB 3.0 cable.

Getting Started

You would think working with an external drive is a piece of cake – and indeed, in most cases, it is simply a plug and play affair. The Western Digital My Book does feature a few twists though.

For one thing, you will find that the drive comes with a second device named Western Digital SES USB Device. This device requests the installation of drivers (which can be found on Windows Update or on the drive itself). This device is responsible for creating a SCSI endpoint to allow for SCSI commands to be tunneled to the drive under Windows, to allow the bundled Western Digital software to perform security features amongst others. Installing this driver is not strictly necessary, especially if not using the WD software, but might be done just to avoid the nagging. It doesn’t affect the speed of the unit whether it is installed or not.

Another twist, which is common for “brand name” external drives, is the use of the USB bridge’s 4k native sector translation. As a result, the drive appears to the OS as using 4kB sectors rather than the 512e that the underlying drive uses, which means that drives formatted and written in the enclosure will not mount properly when directly connected to an internal port. This is clearly seen in the fsutil output below.

Just when you think it ends here … think again. If you’re like me and you’ve bought multiple drives, it might surprise you when you connect them all together to the same computer that only one drive shows up.

The reason, as it turns out, is that the formatting for the drives is done by cloning the filesystem from a master image. This results in all four of my drives having the same volume signature, causing a signature collision that prevents mounting the disk. Of course, if you use them one at a time, that’s fine.

You would think that a storage solutions company would know better but apparently they don’t seem to. The logical solution would be to delete the partitioning and reformat the drives right? Well, this is where strange things happen too. For one, deleting the existing partition results in a new bewildering partitioning scheme coming up …

… one which makes no sense, and one which you are powerless to do anything under Disk Management. You can’t delete the partitions that appear!

So how can we get around this without leaving Windows? You need to invoke a session of Command Prompt with Admin Rights, and then execute diskpart. Then you need to select the disk (make sure you get the right one) and issue a clean command to nuke the partitioning data, which brings things back to sensibility.

Then you can go about partitioning and formatting the drive as you’d like, without any further interference. As to why they made it so difficult, I have no idea. Users of other OSes are probably not going to be bothered by these bugs as their partitioning tools are more advanced and there is a high certainty they would reformat the drives anyway.

However, say you do not format the disk, you are left with an NTFS partition with the following space usage.

The reason the drive isn’t completely empty is purely because of the presence of the bundled Western Digital software which comes pre-loaded onto the drive (thus does not add much production costs). The drivers for the WD SES device mentioned above are also included.

I have a feeling the vast majority of users won’t have much of a use for it, but the bundled software includes the following folders:

Performance Testing

As part of the commissioning process for computer hardware, drives are put through rigorous testing before acceptance. This includes a set of benchmarks. These benchmarks were performed on a different platform from normal – most tests were run on my Intel i7-4770k @ 3.90Ghz running Windows 7, utilizing the onboard Intel USB 3.0 ports on the Asrock Z97E-ITX/ac with the latest P1.80 BIOS and latest v4.0.0.36 xHCI driver from Intel. Drives were initially powered up with all four units connected, but benchmarking was completed with only one unit attached to avoid any potential loss of performance from bus bandwidth contention. No other USB 3.0 devices were attached to the system running the tests.

CrystalDiskInfo

Even without the installation of the SES device driver, SCSI to ATA translation was successful resulting in successful retrieval of SMART data from the drive within the enclosure. Despite the masking of the ID as WD My Book 1230, the drive itself identifies as a WDC WD60EZRX-00MBLB1 – a Western Digital Green drive that is identified as running at 5700rpm. The internal bridge appears only to be running at SATA II rates, although it is unlikely to impact the performance materially.

The left screenshot shows the SMART details as supplied, and the right shows the SMART details after all commissioning tests had completed. All four drives showed very similar values and passed multiple full surface writes/reads without any reported errors or increased error indications, as expected.

Of note is that Western Digital is eliminating the Green branding from their drive lines, and instead rebranding all Green drives as Blue, with a change of the last letter to a Z (e.g. EZRZ), but specifications and support remain unchanged. This seems to be a silly marketing decision to try and boost sales, as Green may have had too many negative connotations from a performance standpoint, and instead, by calling them Blue drives instead, they can “evoke” a feeling of being Mainstream performance devices rather than “bottom tier” devices. But don’t be fooled. Nothing has changed! It probably also helps to reinvigorate the Blue branding which hasn’t seen a “real” Blue drive since the 1Tb was released ages ago.

HD Tune Pro

This drive showed a very different transfer rate characteristic to those I have been used to. Compared to the 4Tb drives tested before, it is clear that the 6Tb capacity really pushes the technology to the limits. Unlike the former drives which had several tens of recording density zones, this drive exhibits a much “smoother” transfer rate curve which suggests a much more numerous number of density zones, to squeeze more data onto the platters. This type of design would not have been capable a decade ago purely because of the complexity of managing so many different zones in regards to physical-logical sector translation, servo placement, etc.

The drive achieved a maximum readback rate of 175.8Mb/s, with an average of 140.2Mb/s and a minimum of 82.8Mb/s. This is a slight improvement over the less dense drives, however, it’s worth noting that the competing Seagate 6Tb internal “desktop” drives which claim a 220Mb/s outer diameter transfer rate. It does, however, just barely exceed the 175Mb/s advertised on the WD Green spec sheet and it is easily purchased as opposed to the Seagate drives.

The write curve follows a similar trajectory, although marginally slower as expected. interestingly, the write access time seems to be artificially low, probably due to command buffering and signalled completion prior to actually committing the write.

Additional tests were also completed, as expected, hard drives are unable to compete with solid state drives for IOPs, and the impact of the USB 3.0 interface’s latency may have impacted upon the results. The write IOPS seem to be higher than the read IOPs, which seems a little surprising.

This is also borne out in the Random Access test, where 512 byte transfers could not be tested due to the drive advertising a physical 4kB sector size. The access time did show high variation especially for write, with bursts of relatively long delay seen.

Only an incomplete file benchmark run was possible, as the benchmark did not co-operate with the drive due to 4kB physical sector size. Queued requests saw no benefit, as expected, as Windows 7 and Intel’s xHCI drivers have no chance of running in UASP mode.

CrystalDiskMark

CrystalDiskMark reflected what we have come to expect from hard drives – namely, smaller random transactions cause them to take a big performance hit. The hit is broadly similar to other drives I have tested in the past.

Using a different test platform (Lenovo E431, Windows 10 Pro, Intel C216-platform USB 3.0 controller) with the SES driver installed, we saw slightly faster performance, although it is clear that the drive did not connect in UASP mode and the SES driver did nothing to provide queued transactions. This is somewhat disappointing, as it may limit the performance of the drive when backing up many small files.

ATTO

Due to the advertised physical sector size, the transfer size had to start at 4kB. The drive saw pretty much full performance for 32kB transfers and greater.

H2testW

No data corruption was experienced throughout testing of all four drives. All drives were broadly similar in transfer rates, although the slowest drive did take almost 20 minutes longer to perform the full run. Because of the way H2testW calculates free space, it was not able to account for the increased filesystem metadata size, so the drive appeared to fill up sooner than expected.

This does, however, illustrate that these 6Tb drives are not particularly speedy, taking about 12 hours to completely read or write. If you were rebuilding a RAID system, doing a disk clone/back-up, you might desire faster speeds.

Conclusion

The Western Digital MyBook 6Tb external drive is based around a Western Digital 6Tb Green drive, placed inside an enclosure sporting a SATA II to USB 3.0 chipset that does not support UASP, and does perform the 4kB sector translation. Its performance was as expected, with sequential transfers pretty much reaching the speeds we expect, although the small-block performance may have taken a hit due to the lack of UASP support. The transfer rate graphs and the fact this is a 6-platter, 12-head design really show just how much we are at the limit of what is sensibly achieved with solely PMR recording designs.

While it is slower than the other contemporary Seagate Desktop 6Tb drive, it is a PMR drive and does not feature any of the surprises you would otherwise encounter in a SMR drive like the Seagate Archive series. At this stage, the Seagate Desktop 6Tb drive is difficult to obtain, and the Western Digital seems to have the upper hand on price, making it the default option for those who want the highest density PMR drive on the market today. However, just be prepared for the 12-hour full-drive read/write times …

If you really don’t need the storage in one drive, you could get a little more storage for your dollar by buying 3Tb units, and if you didn’t need consistent write I/O performance with mostly read-only workloads, the Seagate Archive series internal drives offers 8Tb at about the same price (an extra 2Tb).