According to a report by “icsuperman”, the material cost of S9 miner is around 5,000 yuan. However, the market price for S9 miner in stock supply is around 14,000 CNY at the moment. The profitability of Bitmain has attracted more attention from traditional IC enterprises. The report also points out the merits and drawbacks of the design.

How much is the actual cost of manufacturing one unit of S9 miner? A detailed report was written after the machine was dismantled by “icsuperman”, suggesting that the cost of this mining machine is about 5,000 yuan. The report is backed by  lists of detailed BOM (bill of material).

According to the report, the S9 controller board adopts 28nm Xilinx’s latest Zynq-7000 All Programmable SoC platform. Zynq-7010 is selected as the processor to tightly integrate the ARM processor and FPGA architecture. The unit have the features of high performance and low power consumption of dual-core ARM Cortex of the A9 MPCore (667M) that meets the needs of the machine.

Merits of design:

From the BOM list and the actual PCBA products, it can be seen that the very thoughtful consideration is put in the design of control circuit.

1. Functional scalability have been considered in the design of control board circuit. This control board can support the 9 hashing boards.

2. Independent power supply are equipped with hashing board and separate heat sink are applied to each chip.
3. Package of material is general and no abnormal parts. The quality of the branded material is stable. TI chips is selected for DC-DC of control board power supply. TPS51200 of TI’s industrial-grade product is used to match the VTT, which better guarantees the signal quality.

4. The board connector adopts a lockable socket, which prevents loosening of the cable during the transportation/use of the machine.

5. The PCB layout follows the design rules in a good sense.

No components are not allowed to be placed within 5mm of marking (Red dot in figure 1);
Regular placement of SMT component, no special angle, which leads to efficiency in SMT production and manufacturing;
ETH/DDR and other circuits have been designed with impedance matching to ensure signal integrity.
The reference layer of Power/GND network is relatively complete;
Layout of functional chip is reasonable,
Square shape of PCB and high utilization rate.

Drawbacks of design:

1. The safety clearance is not reserved in part of the circuit of the PSU board.

2. The normal spacing between the TF card holder and the S2 button is not reserved, which is not convenient for the manufacture and after-sale maintenance of DIP plug-in.

3. The NAND FLASH on control board is a bit far away from its power supply chip, crossing ETH and SOC alignment. From the view of design rules, it’s more appropriate to place it closer to FLASH (yellow dot on figure 1).

4. DIP flow indication is not added on PCB LAYOUT. ETH sockets, fan sockets FAN1~FAN6 are not screened with solder mask, which makes it prone to be breached during wave soldering (Red dot in figure 2)

5. PCBA cost is relatively higher. TI DC-DC products can use MPS or Taiwan GMT series to bring cost down.