Disk storage giant WD has expanded its midrange line of NAS boxes, adding some needed performance to the range with the new EX2100 and EX4100 models, offering two and four disk bays respectively. The underpowered My Cloud EX2 and EX4, the original two- and four-bay models, remain but with these new additions to the Expert Series WD is promising decent file write performance – the Achilles’ heel of all budget NAS boxes.

WD My Cloud EX2100 8TB review: Design and build

The EX2100 is based on the same My Cloud software platform, using a now-mature customisation of a Linux-based operating system that is rippling with useful features. Like many NAS vendors, WD has adapted the versatile BusyBox Linux package, adding its own graphical interface, and feeding back its changes by releasing the modified source code as required by the GPLv2 licence. The version employed with WD’s current 1.06.127 firmware is based on Linux kernel 3.10.39, with BusyBox 1.20.2 from July 2012. The hardware to house the disks and processor is more up-to-date and wholly new though, a compact and neatly packaged black box with metal wraparound cover and gently moulded front plastic fascia. The disk are easily accessible from the front, released easily by levers but with no additional locking to prevent prying fingers from popping a disk. Rather than mount the disks in additional caddies or trays, the raw disk slides into the bay, with a strong spring to keep it held firm once the door has been clicked shut. At the back of the unit is a single 65 mm cooling fan, almost silent in normal use, and combined with the quiet operation of the WD Red hard disks inside we have a usefully low-noise storage solution. Powering the EX2100 and helping to keep heat and noise down is a low-power ARM processor. The Marvell Armada 385 is a new system-on-a-chip with dual-core 1.3 GHz processor, backed with 1 GB of memory. Two USB ports are available, both to USB 3.0 specification, one on the front and one on the back. There are two gigabit network ports too, available for use together for link aggregation to increase throughput or for failover security. (Read all  NAS drive reviews.) Power comes from an external laptop-style 48 W mains adaptor, which connects to a single DC inlet on the rear – unlike WD’s more business-oriented NAS boxes there is no secondary power inlet for use as power backup. Overall build quality is excellent, with high standards of fit and finish, making a sturdy unit with no creaks or rattles.

WD My Cloud EX2100 8TB review: Software

The My Cloud firmware is a comprehensive operating system and user interface. From the main page you have a useful overview of the essential working parameters – starting with available capacity in huge numbers, a photograph of the hardware exterior and tick boxes to demonstrate system health and firmware version. Along the top line is a running strip of icons for digging deeper, such as User, Shares, Backups, Storage and Settings. Also available is an Apps tab, where you can download and configure additional applications to expand the unit’s capabilities. Here we found offerings from WordPress, Dropbox and Acronis, as well as two more Bit Torrent clients (aMule and Transmission) available as alternatives to WD’s own built-in BT software. Under the Storage tab you can configure the disk arrangement; with just two disks in the EX2100 you can set these to RAID 1 (as the unit arrives, with one disk mirroring the other for safety); RAID 0 for largest single-volume capacity and best potential speed; and JBOD for separate addressable volumes. There’s also an option for Spanning, which combines the two disks in a linear fashion to swell capacity without striping. Backup options are available to another WD NAS although Western Digital has not included rsync, usually provided to enable backing up to other brands’ storage devices.

WD My Cloud EX2100 8TB review: Performance

The WD My Cloud EX2100 proved to be significantly faster than its cheaper My Cloud predecessors in sequential data read and write speeds. Where the My Cloud EX4 struggled to reach 100 MB/s read speeds, and limped along with writes down at about 37 MB/s, the EX2100 came closer to filling a single gigabit ethernet link – that is, transfers up to around 120 MB/s. We tested the model with two 4 TB WD Red disks in its default RAID 1 arrangement; first in Windows over SMB using CrystalDiskMark storage benchmark. Here we saw sequential transfer results of 103 MB/s for reads and 109 MB/s for writes. Smaller 512 kB data flew by too, at 100 MB/s and 97 MB/s respectively. Digging down to the more challenging 4 kB file level however, the EX2100 struggled to keep up its earlier pace – 4 kB random reads and writes were down to 9.9 MB/s and 4.2 MB/s respectively. But these figures compare well with Synology’s budget DS115j, for example, which recorded similar 4.4 MB/s read speed for 4 kB files but just 2.7 MB/s write speed. In the 32 queue-depth test for 4 kB random data, write speeds were unchanged but random reads rose to 51.5 MB/s. (See also:  Best NAS drives.) ATTO Disk Benchmark was as optimistic as ever, reporting sequential maximums of 118 MB/s for both reads and writes for all data above 128 kB in size. And 4 kB sequential IO here was up to 26.8 MB/s reads and 22.2 MB/s writes. Tested with a Mac on OS X, the performance was less assured. Using SMB to connect over the network we saw results similar to Windows. But this does require you to manually connect in Finder using the ‘Connect to Server…’ function, and type in the full network address of the NAS with the correct prefix (eg, smb://192.168.1.2). We suspect most Mac users will just click on the server share icon offered in the Finder window sidebar, which then makes a connection using the AFP protocol. With SMB in OS X, we recorded average sequential transfer rates of 106 MB/s read and 110 MB/s write, both decent enough figures. Turning to small-file transfers, 4 kB random reads were at 9.9 MB/s and random writes 5.6 MB/s. Averaged over assorted data files scaling from 4 kB up to 1024 kB, results were a creditable 58.2 MB/s read and 49.7 MB/s write. Meanwhile using AFP to connect in OS X, sequential reads were reported at the same good speed, this time 113 MB/s. But large-file sequential writes started to struggle, now averaging 84 MB/s for data 20–100 MB in size. And then fell by 66 percent from the initial speed, to just 37 MB/s for data between 2–10 MB. The biggest issue though was as always with the smallest files, only much more marked than usual, with 4 kB files writing at a paltry 0.07 MB/s. That is one-hundreth of the speed available in Windows or over SMB in OS X. Or put another way, less than one-thousandth of the speed of large file transfers on either platform. Looking across a range of small file types, the 4 kB to 1024 kB average of transfers using AFP protocol in OS X, was 59.6 MB/s reads, and just 3.35 MB/s for file writes. If you’re a Mac user thinking of investing in the WD EX2100, we would advise to connect by SMB only. However if you want to take advantage of the Time Machine hosting capability of the WD EX2100, note that Apple’s backup service will only work over an Apple Filing Protocol (AFP) connection. Your every Time Machine incremental backup, automatically scheduled every hour, can include many small system files and potentially get bogged down by the writing of these small files over the network to this NAS. Note also that WD’s NAS software does not support HFS+, the standard volume format on OS X, so if you wish to connect a Mac-formatted drive you’ll need to wipe and reformat first. Power consumption was remarkably low, as we would hope from an ARM-powered NAS drive. With the unit stressed with various file transfer tasks, we saw a maximum of 18 W power consumption.

WD My Cloud EX2100 8TB review - 74