Quote from: aerobatic on October 30, 2013, 06:14:23 PM

Quote from: DeathAndTaxes on October 30, 2013, 06:10:28 PM

I like the approach taken but the scale is simply unrealistic. For the sake of the argument lets assume the chips (silicon & packaging) is possible at $0.20 per GH/s ($20 per TH). Small runs (less than 1,000 wafers) at 28nm are probably more expensive than you think but lets ignore that and look at the rest of the system.

For example lets try to guesstimate the balance of the system (everything but the ASIC) on a Sierra. Here is my guess what is yours?
case: $60 * 1 = $60
watercooling: $80 * 3 = $240
case fans: $10 * 2 = $20
power supplies: $150 * 2 = $300
PCB (both PCB manufacturing and assembly): $30 x 3 = $90
DC regulators (12V to ~0.8V 200A output ea, 2 per board): $30 x 6 = $180 (probably more KNC uses >$300 per 400 GH/s system)
minor components (connectors, capacitors, etc guesstimate 100+ components per board): $50 x 3 = $150
labor (post PCB assembly, testing, packaging): $50
Balance of system (excluding ASICs) = $1,090 or $908 per TH/s.

That is nothing for fixed costs, markup/profit, yield issues, customer support, shipping losses, warranty, etc.

Now say you could cut that in half and had free raw chips that is still >$5,00 per TH/s. Maybe with enough volume and streamlining you get the cost down to $250 (and assume no yield losses, customer support, profit, etc). Personnally I doubt it but maybe. However your charts starts at $250 and go to just silly numbers like $50 per TH/s. That would be $60 per Sierra equivalent (or $25 per KNC Jupiter). Say I gave you 1.2 TH/s (or 0.5 TH/s) of free chips show me how the balance of the system would only be $60 or $25. Pay close attention to DC regulator (VRM) costs and power supplies they are more expensive on a $/GH basis than you might think.

The power axis is misleading because power in = heat out and then it takes more power to remove the heat. So even an generous (I would say unrealistic) 8 cent per kWh, 20% cooling overhead (PUE 1.2), no real estate overhead, and $500 per TH is more like "end game" of <225 PH/s at current exchange rate. Kinda shows how silly projections of >650 PH/s in less than a year.

i recently did my own guesstimates of the cost and came to very similar conclusions, though i think you're on the low side for the actual asic costs, but i think you've overestimated the power supply and cooling costs, as they appear to be using relatively off the shelf parts, which will be in volume production and they're not paying retail prices for them.

I think this is very critical, because what it shows is what I've always been saying, that the cost of the system is mostly "other stuff" (psus, cooling, case, pcbs, fans) and not the actual cost of the asics, thus you get enormous cost/performance improvements by having faster asics, as the rest of the system doesn't change in cost at all if the asics went faster!

And to reduce the cost of that "other stuff" bitfury did try to build minimalistic PCBs, but so far has had some problems...

https://bitcointalk.org/index.php?topic=251966.msg3425695#msg3425695

spiccioli