Inside the My Cloud 3 TB
The white cover of the WD My Cloud 3 TB can be removed by sliding it forward, which is not a very simple task, as there are some hooks that keep it tight in place. Figure 6 shows the product without its cover.
Inside, there is a 3.5” SATA hard disk with an embbeded control board, as shown in Figure 7.
The hard disk drive inside the My Cloud 3 TB is a WD30EFRX from WD itself. It is part of the “WD Red” series, targeted to NAS applications (designed to work 24/7 continuously). It has SATA-600 interface and 64 MiB of cache. Its rotational speed is not informed by the manufacturer, which only tells it uses the “IntelliPower” technology, which is said to tune the rpm to balance power consumption, transfer speed, and latency. We can guess it is not a 7,200 rpm drive; probably something around 5,400 rpm.
The control board uses a Mindspeed Comcerto 2000 (M86261G-12) CPU, which has two Cortex-A9 ARM cores, running at 650 MHz.