Quote from: dropt on May 07, 2014, 06:27:22 PM

Quote from: bcollan on May 07, 2014, 03:43:05 PM

IMO Bitmain has done themselves a disservice by trying to build a 1TH miner with their existing ASICS.
As an EE and embedded software engineer I see these problems:

1. Bus based systems using card edge connectors - unreliable (see original IBM PC)
2. Beagle board is hobbyist grade - unreliable, known for SD card problems
3. Too many ASICS - unreliable
4. Shipping problems because of #1 above.

The S1 is rock solid because it was designed that way.

1. Two blades solidly attached to a metal frame and connected with ribbon cables.
2. Commercial quality controller in the TP-link

I assume (hope) Bitmain cobbled this together as a stop-gap while they ready their next gen ASICs.

Bitmain responded to customer demand. Quite a number of people had issues trying to colo the S1 because of its form factor and expressed a strong desire for a contained 4U 1TH unit. They (Bitmain) delivered.

As per your other points:

1. I agree that there are and were issues with card edge connetors, but the industry still uses them at large. Manufacturing and electrical component characteristics have come a long way since the 70's and 80's.

2. I agree.

3. Greater number of chips allows for redundency. You can have a single ASIC fail in an S2 and be okay, if you have a Cointerra or HF unit and a chip fails, that's a large percentage of the machines achievable hashrate and would warrant an RMA. In the world of Bitcoin mining an RMA is a death knell.

4. The shipping issues aren't a result of the card edge connectors, it's a result of deficiencies in the mechanical design and packaging. Computers ship all over the world everyday with card edge connectors in place and arrive just fine. IMO there was inadequate support for the guide rails, poor clearances (loose) between card edges and guides, and no mechanical lock securing each card.

Card edge connectors are still problematic IMO. Especially considering they are expected to survive the trip from China with ten relatively large, heavy boards. They are only used because they are cheap. If Bitmain puts in the mechanical components to beef up the card cage and card restraint they will loose the pennies they save over ribbons and DIL connectors. Even the ASICMiner Cube, which used a much superior system of card connection and restraint, had issues with cards needing to be reseated after the trip from China. BTW, the reason I mentioned the number of ASICs is because of the number of large, heavy boards they require.