Review Index:

Western Digital My Cloud EX4 - Personal Cloud Goes Big

Subject: Storage
Manufacturer: Western Digital

Introduction and Features


Today Western Digital launched an important addition to their Personal Cloud Storage NAS family - the My Cloud EX4:

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The My Cloud EX4 is Western Digital's answer to the increased demand for larger personal storage devices. When folks look for places to consolidate all of their bulk files, media, system backups, etc, they tend to extend past what is possible with a single hard drive. Here is Western Digital's projection on where personal storage is headed:

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Where the My Cloud was a single drive solution, the My Cloud EX4 extends that capability to span up to four 3.5" drives. When it comes to devices that span across several drives, the number 4 is a bit of a sweet spot, as it enables several RAID configurations:

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Everything but online capacity expansion (where the user can swap drives one at a time to a larger capacitiy) is suppoted. While WD has stated that feature will be available in a future update, I find it a bit risky to intentionally and repeatedly fail an array by pulling drives and forcing rebuilds. It just makes more sense to back up the data and re-create a fresh array with the new larger drives installed.

Ok, so we've got the groundwork down with a 4-bay NAS device. What remains to be seen is how Western Digital has implemented the feature set. There is a lot to get through here, so let's get to it.

Read on for more on Western Digital's new My Cloud EX4!


I'll kick off by showing Western Digital's feature slide from their EX4 press presentation:

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All of the expected staples are present, such as USB 3.0 connectivity and all common RAID configurations supported out of the box. Many of these bullet points are common among most NAS devices, but there are a few notable standouts. Remember this is a consumer focused NAS, but it has carried over some features from WD's higher-end line. A big one is network redundancy, and more importantly power redundancy - a first seen on a consumer-level device of this type. WD is also proud of their Easy Slide Drive design. Drives install with no caddy and no screws. They really aren't kidding about the 5-second swap. It absolutely can be done that quickly.

Also on this slide we see pricing options, which look really good. Sub-$400 for a bare 4-bay NAS is certainly nothing to sneeze at, and the prices on storage-equipped models are on-par with the cost of adding WD Red drives separately, making the purchase selection almost a no brainer.

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This pic shows the very simply drive swap system. No caddy, screws, keys, or tools needed. Just slide the drive in and close the door. You can also see the EX4 is certainly on the small side for a 4-bay NAS. It ranks amond the smallest 4-bay models we've seen to date.

Internally, the EX4 is driven by a single core 2 GHz ARM CPU connected to 512MB of RAM. The back-end is Linux based, similar to other NAS devices out there, such as the Synology DiskStation.

Before moving on, let's take a look at the connectivity options:

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Here we see everything coming in pairs. A pair of redundant power connections enable a second power supply (available for purcahse separately from WDC) to power the EX4. Next is a pair of USB 3.0 ports for connecting external USB storage devices. Finally is a pair of gigabit rated ethernet ports. These ports can be configured redundantly, as failover, or bonded together (provided the connected switch or router supports it).

We will dive further into these features, software, and apps over the next few pages.

November 12, 2013 | 08:11 PM - Posted by mAxius


November 12, 2013 | 08:22 PM - Posted by Sublym3 (not verified)

Yeah a build your own and a look into RAID alternatives like FlexRAID, unRAID and Greyhole based stuff.

November 12, 2013 | 09:35 PM - Posted by Robert23655124 (not verified)

I agree, I would love to see regular NAS builds (different budgets) and os's with comparisons to pre-built gear.

November 14, 2013 | 04:28 AM - Posted by Anonymous (not verified)

NAS build guide for home use (backup, basic network advice, where bottlenecks exist) would be super useful. Maybe a buyers guide for someone looking at building a small home NAS?

November 14, 2013 | 10:05 AM - Posted by Quix (not verified)

Good work Allyn! Nice review. .. Now slave, MORE STORAGE REVIEWS/INFO! get to work.


November 15, 2013 | 01:27 AM - Posted by razor512

Horrible performance for the price, compare that to building a $400 PC and then installing a bunch of hard drives and setting up RAID 5.

At that price range, it should be maxing out a gigabit connection.

November 15, 2013 | 06:25 AM - Posted by praack

impressed, have been looking for a good system for over a year- have seen some in action - seen the reviews of others- most have failed expectations others were to - well let's face it - how many of us are millionaires!

this looks nice, good combination of featurs - right price

November 15, 2013 | 10:41 AM - Posted by Robogeoff (not verified)

I see that WD states that WD Greens are compatible with this device. I have 4 x 3TB Greens at hand that I could spare for this. How good an idea is it to used Greens on a NAS? I used to hear bad things about Greens and drive failures in NAS devices.

November 16, 2013 | 12:17 PM - Posted by Scimmy (not verified)

I have a home built NAS with WD greens in it. Been running 24/7 for about a year now with no issues in raid 0.

November 19, 2013 | 10:42 AM - Posted by Anonymous (not verified)

Can you add ram to the unit? 512mb seems a bit small when moving large files? Could that improve performance?

November 21, 2013 | 05:45 PM - Posted by David (not verified)

I commend them for allowing redundant power supplies and network connections. That is something most NAS makers usually don't provide on consumer units.

The speed is horrible. Either the unit is defective or they have a big problem with that software. They need to upgrade to the i3 chip and get away from the Atom. It's too slow to do RAID and encryption.

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