At the end of the day it's largely irrelevant what people say, particularly when they are effectively in the middle of a technological arms race to gain share of the network hash rate. Based on their track record I really couldn't see KNC passing up the chance to demonstrate a working 0.07 J/GH/sec chip to the press if they really had one, but they haven't and you have to wonder why.

When engineers make statements that effectively demean their counterparts in other companies, especially those that probably have combined chip design experience an order of magnitude more than the statement makers organisation, then you really know that they are making things up.

The companies you really should pay attention to are the ones that aren't making a fuss over what they may or may not have. Their attitude towards direct competitors also speaks volume about their company, its ethos and its capabilities.

Dogie is bang on the money here, this announcement by Bitfury is simply an exercise in misdirection and PR bullshit. They have had several attempts to make a really high efficiency chip and obviously don't know the recipe. It's easy to say 'my chip can do xJ/GH/sec' without revealing key factors like how big it is (very important), what voltage it runs at and the clock speed at the rated efficiency. In all fairness to Bitmain with their BM1385 they have fullfiled most of these conditions, but no mention of the die size as yet.

To believe that Bitfury can go from an alleged 0.2 J/GH/sec in 28nm to 0.05 in 16nm is nonsense, unless they have very specific measurement points that bear no resemblance to actual operating conditions in practice. 16nm is not a magic bullet - at best you will get half of the power consumption of an existing 28nm design and maybe 2.5 - 3 x the transistor density, very much depending on your design and memory content. KNC tried this same trick with their solar chip, presumably to try to dissuade their competitors and this is more of the same.

The only company that has ever been totally transparent in what they claim to be able to achieve in terms of power efficiency AND tell you how they actually achieved it (eg domino logic) is Spondoolies, and that's largely due to the collective industrial experience of their people and their attention to detail. I'm pretty damn sure that if they were still selling to the public they could come out with all kinds of data about what they could achieve and how they could do it, but they have wisely stayed out of this game and left it to the bullshitters.

By the way, anyone every looked at the size of Bitfurys various 'boards' - they have an awful lot of people to pay......what on earth do they all do? Is this some kind of weird vanity project?

You have completely the wrong view of full custom, a rolled design would be a really dumb idea for a modern mining chip and very area inefficient, the customisation involves only two circuit elements, but I'm sure you know that. Not rocket science at all, no magic, and very little risk if you have some respect for semiconductor physics. DRC is there for very good reasons which again I'm sure you know, and only an idiot would even consider violating them.

Oh, and 'nearly eight figures'?

Thats why you employ people that know what they are doing and use MPW runs. Not rocket science, is it?

Before anyone gets too excited over this development I would wait until you know what the die size is and the operating frequency at quoted power consumption.

I am surprised that they say that full custom poses a higher 'risk' - that's only true for very complex chips like cpu's, not for the very simple (and I mean very simple) functions found in SHA256.

Good luck to them though, anything that puts a spanner in the works of KNC or 21 has to be welcomed.

Don't forget that Litecoin and it's derivatives use SCRYPT which is very ram intensive. Xpoint could make a very significant power saving over the embedded dram used in Litecoin asics, especially if the 3D structures could be integrated with logic and so far there seems to be no indication that they cant.

Their 14nm effort is apparently targeted to 0.15 J/(Gh/sec) at chip level at rated speed. Since 14nm gives roughly 50% power reduction versus a 28nm design then they're still using a cell based approach, ie it's nothing new. It's fine if you're playing with someone else's money and they have very deep pockets, there's 40nm designs that will do much better than this.

Not that it's important - this is just another in a long line of hyped up projects where it doesn't matter if they fail as long as the initial investors get their return when the inevitable IPO hits the stock market.

No, I think they (Andreesen/Horowitz) are greedy predators who don't give a shit about helping good tech companies get established.

What they do know is that the public are suckers and will fall for a hyped up tech project in a future IPO.

Anyone with a decent amount of technical knowledge and a basic grasp of maths can see right through this crap. As for Intel, they most certainly haven't pinned their colours to this mast, have they?

And if Intel really did do those chips then they did a pretty shit job of it.

You might well be correct but they really don't know how wrong things will turn out for them if they start believing that.

Do they think all the companies that pioneered mining chips are a bunch of idiots?

The donors, sorry 'investors' will go for any pitch that they think will make them money as quickly as possible. This was not an Initial Public Offering but there's been plenty of those in the past 50 years where totally worthless businesses get pumped up by their merchant banker partners and go public. There's a huge anticipation (and demand) for the public offering and so the stock will launch at some absurd price, quickly peak then fall back leaving the mugs holding the baby. Some companies survive (lastminute.com in the UK a prime example of this nonsense - annual sales of £250k, market valuation at launch? £800 MILLION) purely and simply because they've been given so much money by idiots.

So don't confuse a good business idea with a ploy to extract as much money as possible from the gullible. This is just another pump and dump scheme, no matter what their publicity says.

On a closing note, if you manufactured a modem, fridge or set top box would you really chance your tech support budget going up by a factor of 100 due to all the problems those pesky little chips will cause your customers? (I'm not making any money ...etc etc)

It's absolute horseshit, period.

I've said it before and will do so again - do the maths.

The future is pretty much coal or natural gas until most of you get to pension age.

Read this if you can get access to a copy: "The Carbon Crunch: How we're getting Climate Change Wrong - and how to fix it" by Dieter Helm.

A lot of it will make your blood boil (especially about renewables and the subsidies they get), but if you're interested in the future of energy generation it gives very good insights.

Bit off topic here, sorry.

This whole 'concept' is a sideshow. Unless you live in the tropics, solar is not viable unless it's heavily subsidised. To buy a 4kW panel at trade prices is still nearly 1,700 dollars, that does'nt include the inverter and other electronics and that price won't  fall much in the near future. Read this article:

www.forbes.com/sites/christopherhelman/2015/05/01/why-teslas-powerwall-is-just-another-toy-for-rich-green-people/

Storing energy in a battery isn't energy efficient, end to end you will be lucky to get 70%.

What would be much more efficient, if a little tricky, would be driving an asic at 0.6V directly from a solar cell. It's a diode, remember? ...... No power supplies, no DC - DC, no power factor. Trouble is, no sunshine at night, and lots of supercapacitors needed for low voltage storage.

Much though I hate to be a party pooper, although it's very nice to see a new mining chip design, especially a dual mode one,
this design is really nothing new, SOI or not. Low w/(Gh/sec) figures can be achieved through simply lowering the clock speed
and/or chip voltage, if you look at the power specs you see that the device in SHA256 mode takes just under 78W at 0.8V at
870Mhz with a hashrate of 139GH/sec. This is it's most efficient point. Why?

At what seems like the lowest W/(Gh/sec), 0.31, the chip is running at 0.6V, 300Mhz and hashes at 48GH/sec. To reach 139GH/sec
performance you'll need to have (almost) 3 devices, each running at 15W. It's more power efficient for sure, but to reach ROI
you'll need to pay a lot more for your hardware. So what's the tradeoff? If you have one machine with, say 16 chips it will take
about 1.6kw at the wall, assuming you use DC to DC converters rather than stringing miners together. The 3 machines with chips
running at 15W will take about 900W, a difference of 0.7kw, or very roughly 500kWh per month. ( A bigger miner with 3 times as
many chips won't save much in build costs)

If your electricity costs 10 cents (US) per month then you save $50 in power, at 20 cents it's $100 and so on. Since the
hashrate of both solutions is identical, the network hashrate and bitcoin exchange rate doesn't come into the equation, so it's
simply a case of power saving per month to see how long it takes to pay for the extra two mining systems.

If each system cost $500 (which is unlikely as you'll see below) then at 10 cents/kWh it will take 20 months for the seemingly
more efficient 3 system solution to break even against the single one, or 10 months at 20 cent/kWh.

For some interesting reading about how chip voltage affects efficiency, see this excellent paper:

web.ece.ucdavis.edu/~anhttran/files/papers/atran_icce10_adder.pdf

It's for a 32 bit adder (which SHA uses as well as single full adders) but it will give you the general idea.


Many thanks to TheRealSteve for pointing  out that the die size is actually given in the data sheet on the packaging diagram.

I have to admit that I missed that, my estimate of the size of the chip is 12.5 -13.2 mm on a side, equating to a packaged device
cost (in volumes of 2 million pa) of $11.4. With the actual dies size of 10.5 mm on a side, that price comes down to $9.1, saving
$37 per 16 chip system. That does make a difference.

To build those 16 devices into a system (without a power supply), pay back $1.5 per device as amortised development costs of
$3 million over 2,000,000 units, test and package and pay it's share of Sfard's ongoing running costs will result in
$360 (ish), so expecting it to retail at $500 is unlikely. $550 gives Sfards a 33% margin which is much more realistic, giving a
cost of $0.27/Ghash. Yes, you would also have just under 30Mh/sec of scrypt which changes the picture quite a bit.

Problem with the scrypt side of things is that the die area of this function is about the same as the SHA256 one, eDRAM takes
up a fair amount of space. Is it worth it? According to the datasheet, in dual mining mode the device will run at 100 Gh/sec (SHA)
and 1.75 MH/sec (Scrypt), so for the 16 chip system:

28Mh/sec will earn about $29 per month before electricity costs, about 50kWh / $5 at 10 cents/kWh, so earning $24/month net

1.6 GH/sec will earn $95 per month (BTC = $220/ Hashrate 370 PH) before electricity, 810kWh / $81 at 10 cents/kWh, earning $22/month net

The total payback of $22+$24 = $46 will pay back the cost of a single machine in 12 months IF the network hash rate stays under 400PH.
Even if you got the miner at cost, it would still take 8 months to pay for itself, never mind making any money. That's also assuming the network hashrate stays under 400PH which I think most would agree is extremely unlikely.

HOWEVER, if you get your electricity at 4 cents/kWH then the net monthly revenue is $74 per month, and if you bought these hypothetical machines in volume (100+) then you might get  them at $450 - then you would get payback in 6 months. Before some forum 'expert' (you know who you are) tells you that in Iceland power costs 2 cents/kWh, you'll only get that rate if you buy 100GWh per annum quantities, and you still have to house your miners and pay someone to look after them. 4 cents is much more realistic.

Oh, and don't forget that 2,000,000 of these chips would add 200PH to the Bitcoin network and 3,5 TH to the Litecoin one .........

Because of the nature of SHA256 you can tell three steps from the end of the second hash if the highest 32 bits are at or below the difficulty target. Got a very good article that describes the whole process in simple to read form. Can't find it right now but I'll post it when I do.

Let the man speak. It's good to have discussions so that the community at large can get a variety of opinions, then make up their own mind as to what's information and what's drivel. Maybe that way some of the drivel might disappear.

And you're absolutely right about the overall efficiency of a product, very good insight.

See? You've probably to taught a good few readers to think differently about design.

No, it's not. A poorly designed power supply can end up costing a lot more than a well designed one. The car analogy is nonsense. Most electronic engineers are not familiar with high current low voltage power supply design, its a specialist area and needs careful selection of components, not to   mention circuit board tracking that provides very low resistance paths (and connections). But the world is full of 'experts', is it not, and that's why shitty designs often result. People simply don't accept their limited knowledge of technical subjects and so don't read enough.

Only if you don't know how to design them properly.