Page 3 - A Closer Look - Hardware (Internal)
There is no wasted room inside the ASUSTOR AS4002T network attached storage. We can see two 3.5" drive bays occupying majority of the area as well as the 70mm fan at the back. A centimeter or so of clearance room can be seen between the rear fan and the two hard drive bays. This allows some space between components to reduce heat congestion. Its well-placed rear exhaust fan can then easily take out the warm air and allow cooler air to flow over the mounted hard drives with minimal turbulence noise. Two differently sized passive heatsinks are used to keep the SoC and 10GbE controller running cool. The motherboard is mounted with its components facing inwards to take advantage of the airflow generated by the sole rear fan as well. Generally speaking, it is pretty packed inside the ASUSTOR AS4002T, but everything is neatly placed and cabled to maximize cooling efficiency.
The power supply is an external brick manufactured by Delta Electronics. The DPS-65VB is a 12V power supply specified for up to 5.417A of current. This means it can deliver a maximum of 65W. As far as efficiency is concerned, it is "VI" rated. To skip over all the nitty gritty compliance details of this technical specification, the basic gist of it is it has to be at least 87.5% efficient in given conditions and consumes less than 0.50W in no-load mode.
Since there is no warranty seal anywhere, there is nothing preventing you from taking a peek inside. In fact, I managed to disassemble the entire system with nothing in the way. The ASUSTOR AS4002T is actually pretty straightforward to disassemble. There were only few screws that holds the ASUSTOR NAS' motherboard to the chassis. I started working late at night as always, and even being a little bit tired, it only took me ten minutes later to get everything out of the way and free the motherboard and SATA backplane from the frame. The SATA backplane ports are powered by a Marvell controller connected via PCI Express. Upon closer inspection, we can see only solid-state capacitors are used. Behind the mid-sized aluminum heatsink is a Marvell Armada 7020 SoC. The Armada 7020 is a 28nm dual core SoC with stock frequency at 1.6GHz. Behind the smaller aluminum heatsink is a Marvell Alaska X 88X3310 10GbE controller. Two Samsung K4A8G165WB-BCRC 1GB DDR4 ICs are embedded on the motherboard for dual channel mode operation. Memory is not expandable by the end user. The system firmware is stored on an ADATA IUM01-512MFHL flash chip.
Other ICs found on the ASUSTOR AS4002T include a MX25L12835FMI NOR flash chip, two MX25L4006E serial flash chips, Microchip PIC16F1829 flash microcontroller, and a Realtek RTS5412 USB 3.1 controller.
Flipping the green motherboard around, and you will find no components of interest here. Since the ASUSTOR AS4002T is a fairly barebones NAS, there is nothing of particular interest here. According to the silkscreen on the printed circuit board, this is the same one used in the four bay AS4004T network attached storage system. Otherwise, every component is soldered on directly to the motherboard; ASUSTOR does not intend the user to upgrade anything directly related to the system.
Lastly, we have the rear exhaust fan and SATA backplane PCB. The Y.S. Tech FD127025HB is a 70mm dual ball bearing fan specified at 0.30A for a maximum of speed of 5000 rpm. The rated airflow is 40.5 CFM and 7.2 mm-H2O static pressure at 41.0 dB of noise. This is the same one found in the ASUSTOR AS3202T. A Marvell 88SE9170 SATA to PCI Express controller can be found on the add-in board shown above.
1. Introduction, Packaging, Specifications
2. A Closer Look - Hardware (External)
3. A Closer Look - Hardware (Internal)
4. Configuration and User Interface, Part I
5. Configuration and User Interface, Part II
6. Configuration and User Interface, Part III
7. Performance and Power Consumption