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.