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WD My Cloud EX4 review: An excellent RAID-enabled home NAS server

Get a bit higher in the sky with WD's new My Cloud EX4, an easy-to-use and affordable four-bay NAS server for home users with an excellent set of personal cloud features. Here's CNET's full review.

Dong Ngo SF Labs Manager, Editor / Reviews
CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers, networking/storage devices, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.
Dong Ngo
11 min read

WD's latest four-bay NAS server, the My Cloud EX4, is a lot more than four single-volume My Cloud units put together.


WD My Cloud EX4

The Good

The <b>WD My Cloud EX4</b> offers data redundancy, Windows Server integration, and an excellent set of personal cloud features. It's also affordable and very easy to use.

The Bad

The server's write speed is disappointing. The mobile app supports a limited number of file formats, there's no search function, and it won't allow you to sort by content type.

The Bottom Line

It's not the fastest NAS, nor does it include many advanced features, but the WD My Cloud EX4 still combines great ease of use into an affordable personal cloud system that's excellent for a connected home.

In addition to having all the goodies of its predecessor, the new EX4 server has many new features, such as support for a variety of RAID configurations to protect data against hard-drive failure. It also sports conveniently designed drive bays and is the first I've seen that can be used with two power adapters at the same time for redundancy.

In my testing, the My Cloud EX4 worked well as an advanced home storage and personal cloud server. Though not the fastest I've seen, the server was very fast, especially its reading speed.

On the down side, compared with similarly configured servers, such as the Synology DiskStation DS412+ or the Asustor AS-604T, the EX4 was still quite inferior in both performance and features. And its My Cloud mobile app still needs some major work to be a viable mobile-streaming option.

To make up for that, the new server is easy to use and a lot more affordable than its competitors, with a suggested price of just $380 (no storage included). You can also buy it with hard drives preinstalled at $800, $950, or $1,150 for 8TB, 12TB, or 16TB, respectively.

If you're looking for a cloud-connected, RAID-enabled server for your home that's easy to use and that you can also easily access on the go, the My Cloud EX4 is an excellent choice. For other options, check out our list of excellent NAS servers.

The My Cloud EX4 has an excellent drive bay design that allows you to replace a hard drive in just a few seconds.
The My Cloud EX4 has an excellent drive bay design that allows you to replace a hard drive in just a few seconds. Dong Ngo/CNET

Design: convenient drive bays with lots of redundancy
Of all multiple-bay servers I've reviewed, the My Cloud EX4 has the most convenient drive bay design with each of its four front-facing bays working like a tape deck. You pull the latch and the hard drive comes out, you push the drive back in and press on the latch to lock the drive in its place. There's no screw or drive tray to work with. With this design, you can literally install or replace a hard drive in just a few seconds. In fact I found this a little too easy since there's no mechanism to keep the latches from being pulled out by accident.

The EX4 supports all standard 3.5 internal hard drives. WD says the company will honor the two-year warranty even when you use certain hard drives from other vendors. The company recommends using its WD Red hard drives that are designed specially for NAS servers, however. These drives are made to be reliable while consuming less energy.

You only need to worry about hard drives when you buy the diskless version of the server. For other options, the hard drives are included and already set up in RAID 5 configuration. RAID 5 balances the performance, data safety, and capacity. Basically you get the total storage space of three hard drives with the capacity of the fourth being used for redundancy in case one of the drives fails. In addition to RAID 5, the server supports RAID 0, RAID 1 and RAID 10. (Read more about RAID here.)

In my testing, the EX4 took a very short time to change from one RAID to another, just a matter of a few minutes. You can easily check on the RAID building process via the little screen on the front, which also shows other information about the server, such as its IP address, its name, and so on.

The My Cloud EX4 is the first home NAS server with two power ports for redundancy.
The My Cloud EX4 is the first home NAS server with two power ports for redundancy. Dong Ngo/CNET

On the back the EX4 shows a true dual configuration: there are two USB 3.0 ports, two Gigabit Ethernet ports and, the first I've seen, two power ports. You can use two power adapters (only one is included) with the server to guard against the case of one of them failing or being pulled out by accident. The server works with just one network port, but by having two, it offers more options for load-balancing and redundancy. You can use the USB ports to host more storage via external hard drives.

Plug and play setup
If you buy a diskless version of the EX4, you will first need to install the hard drives by yourself and set up a RAID configuration. You should only do this if you're an advanced user, and if you are you won't have any problem getting the job done. After that, or if you get a model with a hard drive preloaded, the setup process is very similar and basically the same as that of the My Cloud. You won't even need to know about RAID.

By default, the server comes with three public share folders called Public, SmartWare, and Time Machine Backup. As the names suggest, the Public folder is for storing public data, and the other two are for backups of Windows and Mac machines, respectively.

As soon as the device is plugged in, without you doing anything, all of these public folders are available to all connected devices in the home network. From a Windows computer, you can browse for these share folders and copy data (such as digital content) over. Macs will immediately see the My Cloud as an available destination for Time Machine backup and the My Cloud will also appear on Finder. All DLNA-enabled network media player devices, such as the WD TV, will also immediately find the content stored on the server for streaming purposes.

Now, from within the same home network, if you download the My Cloud mobile app (available for iOS and Android), the app will see and connect to the My Cloud EX4. After this first step, now even when you're out and about, connecting to a different Wi-Fi network or using a cellular connection, the mobile app on your device will maintain access to the My Cloud EX4 server via the Internet. In other words, there's no extra setup or log-in needed to make the app work with the server remotely. Now if you want to add a remote device, such as one belonging to a friend who lives in a different city or country, to the server, you can create an access code and sent it to that device using e-mail. (More on this below.)

The WD My Cloud EX4's Web interface resembles that of the My Cloud, well-organized and easy to use.
The WD My Cloud EX4's Web interface resembles that of the My Cloud, well-organized and easy to use. Dong Ngo/CNET

In all, if you use the My Cloud EX4 by yourself or share it with a group of people with no need for data privacy among themselves, there's really nothing to setting up the My Cloud, other than plugging it in and downloading the mobile app. Now, if you want to further customize the NAS server, that's also quite easy to do. In this case you will need to first download the WD My Cloud Setup software from WD2Go.com and install it on a connected computer, whether Windows or Mac.

Helpful software and Web interface
The WD My Cloud EX4 comes with the same software as the WD My Cloud. These applications are basically self-explanatory and are available for both Windows and Mac, except for the WD SmartWare backup program, which is only available for Windows. This is because the server supports Time Machine backup natively.

To make changes to the settings of the server, including turning its features on and off, adding more users, and so on, you will need to use the server's Web interface. To get there just point a connected computer to the server's IP address or click on the Dashboard icon created by the WD setup software.

The EX4's interface resembles My Cloud's: well-organized and easy to use, with access to all of the server's customizations and settings.

As with its predecessor, the biggest selling point of the My Cloud EX4 is the Cloud Access feature. This feature allows you to sign up for a WDMyCloud.com online account for each user account of the NAS server, and to create an access code for a remote device.

Apps are now supported, including third-party apps.
Apps are now supported, including third-party apps. Dong Ngo/CNET

The online account with WDMyCloud.com basically allows a VPN-like connection over the Internet for computer users. For example, when you're traveling away from home, even in a different country, then from a computer connected to the Internet you can point the browser to WDMyCloud.com and log in with the WDMyCloud account, and with a click you can quickly create a network drive linked to a share folder on the My Cloud NAS server at home. This means you can just drag and drop files between the computer and the server as though the two were on the same local network. This is similar to VPN access though there's no VPN connection. (Note that the speed of data moving between the remote computer and the NAS server depends on the speed of the Internet at both the computer and the server end.) You can also quickly disconnect the mapped network drive when you want to disconnect the remote computer from the server.

The access code for mobile devices would be useful if, for example, you want your friend who lives in a different city to be able to share data with you via the My Cloud. Just create a user account for that person on the NAS server, create an access code, and give the information to him or her. Your friend then can download the My Cloud mobile app, run it, and enter the code. Now your friend can use the My Cloud without ever having to be anywhere near the server, physically.

Both the WDMyCloud account and the My Cloud mobile app support multiple WD servers (true of both the My Cloud and My Cloud EX4). If you have more than one server, you have the option to pick which one you want to connect to at a time and it's very easy to switch between them.

The My Cloud EX4 supports all backup methods you can think of.
The My Cloud EX4 supports all backup methods you can think of. Dong Ngo/CNET

Good app for mobile backup, but limited for streaming
The My Cloud EX4 works with the same My Cloud mobile app as the My Cloud. Since my review of the My Cloud this app has gone through one update, but its functionality remains very much the same and rather limited.

The app allows you to remotely access the public share folders as well as the private share folder of the current user. You can quickly download files from the NAS server to the mobile device or back up files, such as photos and videos, from the mobile device onto the NAS server. You can do more than one of these tasks at the same time, making it an excellent backup server for those who love taking photos and video with their phones. In my trials, the backing-up process worked well with smaller files, such as documents or photos. When I wanted to back up a large file, such as a 30-second video recorded by an iPad, the performance was slow. But this depends a lot on the connection between the mobile device and the server. For obvious reasons, it generally works better over Wi-Fi than over a cellular connection.

While the backup function worked out OK, the My Cloud app's playback function was mediocre. For one, it only supports browsing content by folder, meaning you have to remember what you want to play back and where it is. There's no search function, either. Generally, it's OK if you want to play back a video, but for music and photos, it's such a pain, especially because while you can easily dig deeper into subfolders, there's no "back button" way to go back to the previous level of folder browsing, making the whole thing quite quite awkward.

The support for media streaming is also extremely limited: you can basically play back only the types of content natively supported by the mobile device. And only music can really be streamed; other content needs to be first buffered (temporarily downloaded) onto the mobile device before it can be played back. For example, if you want to view a photo that resides on the My Cloud NAS server using an iPad, the mobile app would first buffer the entire photo onto the mobile device before displaying it. This makes viewing even a small photo take quite a bit of time and makes it virtually impossible to stream video over a cellular connection.

In all the My Cloud app has a lot of potential but it will need a few major updates to be a viable remote-streaming option.

Lots of backup options, business features added
In addition to offering what the My Cloud does, the My Cloud EX4 now also supports a few business features, including iSCSI, Active Directory, and volume visualization. On top of that it now has an Apps center from which you can download and install more applications that add more functions and features to the server. Currently there are just a handful of apps but hopefully that will change in the future.

Support for third-party apps is a major development for WD's NAS servers. This brings the My Cloud EX4 a bit closer to other high-end servers on the market. The Synology DS412+, for example, has hundreds of apps to offer virtually all you can expect from a network storage device.

The My Cloud EX4 comes with all type of backups you can think of for a NAS server. You can back up content from one place to another within the server, between the server and connected USB external storage devices, between multiple EX4 units in a local network or over the Internet, and up to a cloud service, such as Amazon S3 or ElephantDrive.

Fast performance for home
I tested the My Cloud EX4 with RAID 5 and it offered very good performance at 51MBps and 90MBps for writing and reading, respectively, via a Gigabit Ethernet connection. Compared with the My Cloud, the EX4 was slightly slower in write speed but much faster in read speed. Compared with other similarly configured NAS servers, the EX4 was below the average in writing and above the average in reading. The Synology DS412+, for example offered data rates higher than 100MBps.

CNET Labs NAS performance (via wired Gigabit Ethernet, measured in MBps)
(Longer bars indicate better performance)

Considering the cost, however, the My Cloud EX4's performance was still excellent. And for home use, it's more than fast enough. The server can easily handle multiple data-intensive tasks at a time, such as backing up multiple computers while streaming HD video to multiple network players. The server also worked very well in my testing and remained quiet and cool even during heavy loads.

The My Cloud EX4 is a big step up from the original My Cloud, offering data redundancy, apps, excellent drive bay design, and a handful of business features. The server's data rate wasn't the best I've seen but it more than makes up for that with ease of use and affordability. At the suggested price of $380, the diskless version, for example, costs just about two-thirds as much as its Synology DS412+ counterpart.

For a connected home, or even a small business, that just needs to share a lot of data, both locally and via the Internet, the My Cloud EX4 makes an excellent investment.


WD My Cloud EX4

Score Breakdown

Setup 9Features 8Performance 7Support 9