Question for S7 -
Bitmain says all three PCIe connectors on each board must be attached. Does anyone know if miner will work with one open on a board? In other words is this a hard and fast rule or is this for ideal performance?
It comes down to how many amps of 12VDC per Molex pin. the more amps being stuffed through each pin increases the heat generated in the pin, the pin to socket physical contact connection and at the solder connections.
Lets say the unit uses 100A of 12VDC. You have 3 Molex 6 pin connectors per hash board x 3 hash boards. In the molex connector 3 are positive DC, 3 are negative DC. I have no clue how many amps the controller uses so I'll just focus on the hash boards. ANALOGY : Picture the power supply as a water pump in a bucket. You turn on the pump, water flows through one hose,that is positive, it goes to a water cooling block for a cpu, the hot water exiting the water block enters another tube and goes back to the bucket, thats the negative.... so each positive and negative pin is a circuit and can only pump just so much through the circuit. What I'm getting at is, even though you use two pins, 1 positive and 1 negative, you are NOT adding the amperage capacity of the two pins together, both pins are the same "hose", basically, what goes through one end of the hose comes out the other.
A total of 9 Molex connectors, That would be 27 pins for positive and 27 pins for negative. 100amps of 12VDC divided by 27 equals 3.7A of 12vdc going through each pin.
Now if you reduce the amount of pins by not using ALL the molex connectors with your power supply, you will increase the current going through each pin. Using 2 Molex connectors per hash board equals 18 pins positive and 18 pins negative. 100A of 12VDC divided by 18 equals 5.5 amps going through each pin.
Each pin of the Molex Mini-Fit Jr. connector is rated for 9A maximum. So the pin and the mating connector would handle the current going through the connector if using just 2 connectors per hash board. BUT, how is the circuit board designed? Is the circuit board designed to handle the additional heat generated by just using 2 connectors? I would not think so since adding additional layers of heat dissipating copper in the layered fiber board would cost money and we all know Bitmain is in it for the cashola. My guess would be that if you use just 2 of the Molex connectors per hash board, you will find that the circuit board will start to discolor and or the Molex connector due to the excessive heat generated. You will also find that the voltage will drop under load at the hashboard causing inefficiency.
Does anyone have any information as to WHAT IS NEXT? 
