WD My Cloud EX4 8TB Personal Cloud Storage NAS Review

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WD My Cloud EX4 Performance Benchmarks

To check the performance of the WD My Cloud EX4 8TB we ran CrystalDiskMark 3.0.3 x64 with the default settings. This is a quick and easy storage drive benchmark utility that shows the peak sequential and random read/write speeds.


The WD My Cloud EX4 topped out at 49 MB/s read and 48 MB/s write. These aren’t the fastest speeds that we have ever seed, but not bad for a NAS that is powered by the Marvell ARMADA 300 SoC at 2.0GHz with 512MB DDR3 memory.


Rather than relying on synthetic benchmarks alone, we also used Teracopy and dragged and dropped a folder with 400 pictures and .MOV video clips from a recent trip we took to Hawaii last month. The entire folder was 2.21GB in size and is the perfect real world test for the My Cloud EX4 as everyone backs up their pictures and movies.  When copying the pictures from our desktop through our Gigabit LAN (powered by the ASUS RT-AC66U Gigabit Router) to the My Cloud EX4 we averaged 25 MB/s.  It tool 89.59 seconds to copy the 2.21GB file to the NAS, which means that we are certainly not going to be breaking any speed records here today.


When copying the folder from the NAS back to a new location on our desktop PC we found that it took 91.30 seconds at 25MB/s once again. The WD My Cloud EX4 is extremely user friendly, but it is clear that transfer speeds are not going to be it’s strong suit.

It should be noted that we tried faster 7200RPM WD Black hard drives and the performance was the same.  This means that the limitation is likely the single-core Marvell ARMADA 300 SoC running at 2.0GHz as it is not the drives.

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  • Falcon89

    Does anyone know what size barrel jack this uses? I need to rig up an ESP8266 to cut the power when it needs reset (these freeze a lot- not enough RAM or processing power- esp RAID5)

  • Antonio Chinnici

    Thanks for your review. Before reading it I was thinking to buy it. I need to have a first NAS, at my office, with capacity of 16TB in Raid 5 with its reasonable price. Now I’m not sure it’s the good product I need to use.

  • GT3

    I have the 16 TB version of this NAS and I wish the fan was a little quieter as the NAS is in the living room. I wanted to work around this by setting automatic startup and shutdown times. However THAT really sucks because you can only set a single starttime and shutdown time per day. And the shutdown time can not be later than midnight. So if you’re often up till 1 AM the function is useless. Also it will force the shutdown even if you’re currently streaming or copying files to the NAS. Pretty poor design.

  • basroil

    Shame that the speed are not even a quarter of what gigE should have, I was actually considering this one since I have had pretty damn good experience with WD drives in the past (of a dozen drives just one failure, and that one that failed was my first 500gb drive from them, which had been relegated to third level backup duty)