Hello fellow miners,
I invested into 2x Neptune 1st batch preorder hoping to get the units fast and expected them to break even quickly. Now I'm getting really worried because of fire hazard KnC Neptune introduced into my house! BTW - is your stuff UL certified, this is a must for insurance!
Both units arrived, total of 10 cubes. I was aware of KnC recommendation on power supplies. I went with IBM 835W power supplies, using 1 per cube. There is a separate power supply that drives the motherboards. Each power supply was load tested to ensure that it can do the job. Fun!
I was also aware that PCIe power connector is rated for up to 75W of power. Look on video cards - there is 2 connectors, right? 6 pin each, up to 25W per AWG18 wire. You can draw up to 150W from a single connector, but you have to upgrade to AWG 16 wires. Guys from molex came up with this design and I'm sure they have tested it before they released it to the real world.
Here is my setup:
2 boards, 10 12.0V power supplies 835W under load each, all connected using custom made AWG 16 wires (the pins for AWG16, crimped and then soldered to ensure best possible contact). Actual power draw is around 350-400W per cube, flowing through single PCIe connector! All configs are stock, no overclocking because KnC used cheaper DC/DC convertors hoping to cut costs down (total 8 DC/DC modules per cube, rated at 40A. 50A ones would cost $0.35 more).
Recently 3 out of 10 cubes failed. You probably guessed by now - PCIe connector. It is not rated for such load. Power supplies tripped and shut off the failed cubes as wiring shorted. Power cable connector melted into power socket on the board! I had a lot of fun replacing the socket - there is some kind of extra tough solder used - it took me almost an hour to do 1 socket with my 40W soldering tool. 2 more to go. I'm about to have best weekend ever. 30% failure rate for a "mature" product in 2 month operation.
Should I invest into fire suppression system? This is the most power hungry miner I have at the moment. Worst possible engineering!
KnC: was it really hard to put 2 connectors, next to each other? Or 3? Or 2x8pin ones? I hope you enjoy $0.36 of savings per cube! Take a look on the stuff that intron does - he puts 2 (!) connectors on a board that will draw ~280W. Look at avalon - their original design was not bad at all. Look at metabank - it was great since the day one. Finally - please look into the boards that marto74 develops - he also has open source ava3 design - you could pick up some tricks from his boards!
I also would like to say thank you for SPI cables being short and ugly. It is 2014, we have USB3 and PoE technologies for our disposal, right? There is also a selection of NCU chips available! Is is really hard to develop a firmware that will operate 1 cube over USB - you claim to have a few "skilled" engineers on staff! RPi board is cheaper than custom BBB and cheaper than that board you managed to put FPGA onto!
Pictures are here and here
P.S. I though Jupiter was a failure - no custom design, just a hardcopy from FPGA done by Altera - fastest and cheapest way to claim that you have ASIC. Hardware engineering was horrible - 3 of 4 modules had fans detached during shipping - imagine what would happen if I wouldn't inspect the unit prior to power on? Neptune is even worse - the cube seems solid - this gives false security feeling - mother of all f%#k%ps!
KnC, I see you managed to put a chipart into Titan chip - how long did it actually take you? A month? This is really the only thing you can be proud of - eyecandy. Even BFL was better with their power design!
