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October 25, 2016, 06:49:47 AM *
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1  Bitcoin / Mining speculation / Re: Need help with Future Bitcoin Farm on: October 20, 2016, 01:47:14 PM
This looks like a real opportunity for some scam artist to earn serious consulting fees.

Last century, when I was still working in the entertainment business we one prospective investor like that. He was a son of the owner of a chain of used car lots that catered primarily to Spanish speakers in southwestern USA. He wanted to start a rap label catering to non-English speakers. I don't recall the actual money invested wasted, but it was in the range between $1M and $100M. It was completely integrated, it had A&R scouts, recording studio, duplicating plants and marketing organization. All went to waste because none of it sold, although some of the artists they signed were later successful under new names and new management.

I haven't personally met the guy, but I read his e-mail and spoke with many of his "advisers" and "assistants". The lack of though and introspection is very similar. It is an opportunity for e.g. newly minted lawyer who needs to pay of his school loans. He won't pocket the whole money but will nicely earn during buildup and inevitable liquidation.

The guys I used to know got a lot of free limousine rides out of the above "deal". If this guy is real then be prepared to ride some uncomfortable but very fast cars.

No kidding, this looks like a real opportunity for some smooth, but ruthless operator who doesn't mind having to do some butt kissing when it handsomely pays. Just lawyer up appropriately, those kinds of scams aren't prosecuted in the USA because they involve "accredited investors."

Edit: Along with kissing butt, you will probably need to kick butt. Feel free to abuse me verbally as a "naysayer", "banker's stooge", "statist", etc. I don't mind. It is part of the entertainment in the front row.


I am just kind of new in the Bitcoin space. I've done some research about how to mine and how this works. Myself and a potential investor friend want to build a considerable big Bitcoin Farm. I have several question that I need from real experts to help me build the business plan for this future company.

Note. Please remember that I am not an expert and also capital is not an issue.

1) Where is the best place to build a big bitcoin farm? Washington State? Iceland? or what is your suggestion?

2) I just discovered the Bitfury Data Center ( If its better to build one similar or this is the best option in the market? I received the quote for this Data Center and its $2.5 Million. Its worth it? If so, why?

3) How many bitcoins I can get per day with that Data Center? They told me the capacity is 15PH and 2MW of power. What this means?

4) What other costs are involved when building a bitcoin mining center?

5) How many people I have to hire? Do they have to be Engineers? Technicians? What exactly?

6) I want to generate between at least 5000 bitcoins monthly. What Equipment do you suggest and what is the cost?

7) Are there any Taxes to pay if you get bitcoins in the US? what about Iceland?

8 ) How much is the electricity cost?

9) How and where to  store 5000 Bitcoins per month?

10) Is there a tracking software to keep monitoring all the bitcoins generated?

11) At that large scale how to prevent hackers or employees to steal bitcoins?

I appreciate your responses in advance and thank you very much for the help.

2  Other / Meta / Re: AGD's ignore list extreme on: October 18, 2016, 03:22:39 PM
Danny's list started as a list of people whose arguments he couldn't refute, so he started advocating ignoring them as a signature spammers. The best example is MPOE-PR who never participated in any paid signature campaign but mercilessly  and very skillfully poked fun at some of Danny's arguments. Anyone ignoring MPOE-PR would miss some of the best satirical and critical writing on Bitcointalk, although the account is no longer active.

The list also includes me and several other long time members who had poked fun at Danny and other former stalwarts turned later scammers like DeathAndTaxes.

The list may be statistically correct, i.e. the majority of the names on the list are or were wearing paid signatures and spamming them. But the list also includes multiple people involved in scam busting. And therefore becomes a danger to the newcomers who won't be able to see the warning and explanations of the old scams.

About the latter additions I have nothing to say, neither positive or negative, I wasn't really paying attention. I'm mostly interested in scams not spam.
3  Bitcoin / Development & Technical Discussion / Re: How to start mining in offline? on: October 01, 2016, 12:02:49 PM
Conceptually your ring of 4 peers looks correct and should be capable of mining. I don't know why it isn't working for you.

The only thing I can suggest is to search the net for the phase "testnet in a box". There are multiple pages describing exactly how they did it. Just retrace exactly their steps. I've done it multiple times, but my computers used for testing are in storage and I can't look at them now.
4  Bitcoin / Development & Technical Discussion / Re: How to start mining in offline? on: October 01, 2016, 05:28:40 AM
For the Bitcoin Core client to start mining it requires some minimal rudimentary peer to peer network. If I remember correctly the minimum is either 2 or 3 peers. You actually don't need the separate computers, the necessary peer to peer network can be created on a single computer by running multiple Bitcoin Core instances under multiple user accounts.

I don't remember the details, you'll have to experiment with starting multiple instances of Bitcoin Core with several flags: -connect=? , -port=? and -rpcport=? .

Edit: If I remember correctly such setup is not called "offline mining", it is called "testnet in a box", even if you aren't running testnet.

Also, research older versions of cgminer that still supported GPU mining of Bitcoin to use for your tests. GPU mining is much more power-efficient than CPU mining. With a mid-range laptop (couple of years ago, when GPU mining of Bitcoin was still a thing) you should be able to run all the required programs (multiple instances of Bitcoin Core and at least one instance of cgminer) on batteries and without spinning up the laptop's fan or having to suffer a hot laptop. Even if you work on a desktop and not on the laptop, the power savings and the fan noise reduction are really helpful for the developer.

5  Bitcoin / Technical Support / Re: How to pull big data from the blockchain? on: September 23, 2016, 11:31:08 PM
You lost me? Is that a line from Minority Report?
Yes, not a line, but a reference.

That also still does not answer my question. Maybe something was lost in translation. Say a person wanted to find out how many bitcoins were "moved" in a 24 hour period on the blockchain, or a 7 day period or 30 days, so they could compare that day, week, month to previous days weeks and months, are you saying that the data in the blockchain which would contain the amount of bitcoins moved or involved in transactions can not be pulled from the blockchain itself anymore?
When you move a $20 bill from your left pocket to your right pocket do you consider that a transaction?

When you pay for a $3 pumpkin spice latte with a $20 bill what is the transacted volume?
6  Bitcoin / Technical Support / Re: How to pull big data from the blockchain? on: September 23, 2016, 10:25:40 PM
Are you saying you cannot accurately tell how many bitcoins are sent in a given period any more? If so, then bitcoin is far more interesting as a fiat alternative than i could have ever imagined. 
Yep, my nose can sniff pre-crime before the criminal can even conceive the details of the future crime.  Cheesy

And I don't live in a pool of physiological salt solution.  Grin
7  Bitcoin / Technical Support / Re: How to pull big data from the blockchain? on: September 23, 2016, 10:04:58 PM
I'm not even going to pretend i understood all of that as although i have heard of MtGox in passing, i know nothing of Dwolla, as i am fairly new (less than a year) to bitcoin. Are you saying that somehow they used Excel spreadsheets to scam bitcoins from them? It was my understanding that in order to steal bitcoins (without getting someone to send them to you then not delivering a good) you needed to have the private key, and thats what made BTC secure.

Not that i am a super genius or anything, but in my short experience, i dont see how harvesting data from the blockchain allows you to steal bitcoins. Isn't that data available to anyone with the right piece of software? Maybe you could fill me in a little more, not that i am trying to pry, but by what you have stated about scammers asking about how to pull data from the chain, i don't see how having that data would allow them to scam. Any insight would be appreciated, In my short time with bitcoin, I realized how little I know, and how much I have yet to learn, which was part of my curiosity about all the data in the blockchain.
The case MtGox vs. Dwolla wasn't about stealing bitcoins, it was about stealing dollars. They had some sort of net-transfer agreement to needlessly transferring dollars back and forth. The reports/invoices used in those bank transfers were created using bogus harvesting algorithms. The bogusness wasn't complete, it sums in the spreadsheets were close enough to real ones that the respective CEOs/CFOs signed them off as "true and accurate under the penalty of perjury". I don't remember further details, they were briefly described in some exhibits to that lawsuit.

Ask yourself a question: you were planning on computing some sort of "transaction volume" aggregate. The bugs that allowed to distinguish "payment" output from "change" output were fixed years ago, when Hal Finney was still alive. So what were you planing on doing to truthfully compute that in 2016?
8  Bitcoin / Technical Support / Re: How to pull big data from the blockchain? on: September 23, 2016, 09:34:25 PM
Thanks for taking the time to be considerate on not write me off like a nut job as most people on this forum would have. You are of rare kind good sir!
This is the reality of the Bitcoin milieu. There are many people coming to this board with request of supporting strange combinations of tools. Frequently this is because Bitcoin's (near-)immutability has created a problem with somebody's preexisting fraud or scam.

In my memory the most visible case of importing Bitcoin data to Microsoft Excel was highlighted by the MtGox vs. Dwolla lawsuit. I'm not going to try to pass the judgement on who was to trying to scam who in that case. But spreadsheet's easy mutability makes them perfect tool for perpetuating scams.

This is not to say that you are a scammer. But so many scammers have asked similar questions to yours that now the onus is on you to differentiate yourself from the previous people.
9  Bitcoin / Technical Support / Re: How to pull big data from the blockchain? on: September 23, 2016, 07:07:25 PM
Thank you very much for the clarification.

Sorry, I didn't think any of that info was relevant at the time as from what I saw on this forum, too much info often results in people passing over your post, and because I am not looking to hire anyone to do it for me, more so just to find out if there are more user friendly options out there, preferably windows based.

To answer your question, first starts with a little more explanation, Sure the blockchain certainly qualifies as "big data" in its entirety, but the data I hope to extract from it is very far from "big" in comparison, transaction volume, lists of addresses used, positive balance addresses etc. still would only number in the few millions of entries, Microsoft Excel has a max row height of 1,048,576 rows, so a few page workbook could handle most of the data, although most often for analytical purposes I use Microsoft Access. Formatting the data once extracted is not such a big deal as typically i can find someone on Fiverr to write a simple java app that would parse and convert the data from the format I receive it in to the format I need to import it into excel, access, or on occasion tanagra.

Again, that being said, if your reply was in hopes of finding a paying client, I am not the one. At most I spend on my projects of curiosity is $5 - $25 for someone on fiver to do something for me. This thread was more to find out what if anything is available in the bitcoin space that is not solely linux or advanced computer programmer level stuff.

No, I am not looking for any clients. I was just trying to get a better "sniff test" on who's asking.

In my experience, the reason that you aren't getting any suitable answers is that you don't look like somebody who isn't interested in learning anything new. Microsoft Office could be actually quite helpful, but you would have to learn how to set up proper Microsoft SQL backend for Microsoft Access and utilize the OLAP functionality there. With the clarification above you made clear that you even aren't a wannabe in big data.

I originally thought that you are something akin to a new instance of the German crackpot LvM (;u=103358) with his "BTC violates GAAP, result a mess." ( . But then you wrote like somebody who is forced to use Windows because of the organizational constraints, not because you just "don't wanna".

Thanks again.

Edit: Fixed grammar: double negation removed.

10  Bitcoin / Technical Support / Re: How to pull big data from the blockchain? on: September 23, 2016, 05:04:00 PM
Thanks a bunch, i tried google, bing, and stackexchange extensivly over the past 24 hours to look for a windows version with no resolve, it would be awesome if such a thing was out there for us lay-persons.
You know, to get better help you should describe the tools you are planning on using to analyze the data once you get it. What kind of software you already have and are familiar with? What kind of hardware do you have available? Have you ever actually processed some really big data-sets on your own, without using external database?

In my previous company we had certain class of prospective customers that are just not worth dealing with, not even worth the salesperson time spend talking. Somewhat contrived example to maintain privacy: a department has site license for a non-current version of SPSS for 32-bit Windows, and always inputted the data either in the old dBaseIII+ format (2GB limitation) or used Oracle ODBC driver for 32-bit Windows (with the actual data on the mainframe/cluster). This is the type that isn't worth helping, even though they have budget to theoretically buy a working solution, because they don't understand their own tools and they've been doing bullshit GIGO for years. Any money gained isn't worth the time it would take to support them.
11  Bitcoin / Development & Technical Discussion / Re: WTF? bitcoin-qt Wallet Passphrase in history??? on: September 16, 2016, 05:04:58 PM
Please carefully read the manpages for . Depending on the version and the settings it is capable of saving history per each application linked with .
12  Bitcoin / Development & Technical Discussion / Re: Technically feasible to play chess using Bitcoin? on: September 15, 2016, 11:50:59 PM
Yes, that's fine for my purposes. As I told the other person above, this is a learning exercise to explore what Bitcoin is capable of.
The point of using Bitcoin is that we want its blockchain to know the program and the inputs and verify the output, then release funds depending on the output. It isn't enough that both you and I can run the program off the blockchain, because one of us could lie and say "hey when I run this program it says I won, so give me the money." Trustless here means you don't have to trust your partner to be honest and pay you if he loses. The blockchain resolves any dispute about who the winner is, and causes funds to be paid to them.
OK. So we have fairly unsophisticated but way too large (for current Bitcoin blocks) program to verify the result of the game. We could say it is doable with a future soft fork.

The only remaining problem is how to verifiably enter the moves of the players into that program. Do you want to do that (1) one by one (2) in pairs (3) entire game in one fell swoop? I guess we now have a "trustless move

After the soft-fork gets implemented the whole operation would be:

<white-pubkey> <black-pubkey> OP_OFFICIATE_CHESS_GAME

which pops two public keys of the stack and pushed one of three numbers {0,1/2,1} back onto the stack.

So you are back into square one of Bitcoin: at least 50%+ of miners have to have the correct implementation of OP_OFFICIATE_CHESS_GAME soft-forked operator. It isn't a technical problem but a political one.

More precisesly: it isn't 50% of all miners, but of those miners that implement and mine OP_OFFICIATE_CHESS_GAME a majority (>50%) have to use the correct implementation.
13  Bitcoin / Development & Technical Discussion / Re: Technically feasible to play chess using Bitcoin? on: September 15, 2016, 11:04:37 PM
The smart contract would not be generating moves. Just officiating a human vs. human match. I have in mind something like in the article I linked to. Checking whether a move is valid is far easier than generating good moves.
I'm sorry, I misunderstood your intentions.
Timing moves is tricky, however it may be possible to play long games where the time per move is measured in blocks. If the time is long enough (for instance, 100 blocks per move), the variance of block creation may not be an issue. However since the goal is not to post every move on the chain (as mentioned in the original post, this is super inefficient), there may be some way to play with faster time controls with all verification done off-chain or over a Lightning channel.
But judging the game isn't just verification of the moves. Most of the effort in judging actually goes to verifying the fairness, meaning that any of the sides isn't using any disallowed resources. So it would not be "human vs. human" but more like "correspondence game with unlimited computing resources and unlimited consultation".
I mention zero knowledge proofs because those are solutions that Greg mentioned already exist (ZKCP) or are eventually coming (SNARKS). You're right that it seems like zero knowledge shouldn't be needed for this. If anyone knows how to trustlessly verify an arbitrary computation without it, I'm interested to know how.
Is that a trick question? If you know the computation program and the input state then just rerun that computation as many times as you want until the you are convinced. Do you have some strange definition of "trustlessness" in your mind? Something like "left hand doesn't trust right hand?"

I think chess programming is just a nice way to really learn a new programming languages. It is non-trivial yet small enough that interesting and sensible programs can be written by a single programmer. Other than that what is the point? It really is "play to play" not "play to win".

14  Bitcoin / Development & Technical Discussion / Re: Technically feasible to play chess using Bitcoin? on: September 15, 2016, 07:39:34 PM
If this is not possible, what is keeping it from being feasible?
Competitive chess playing is very resource intensive: fastest multicore processors, gigabytes of hash tables for middle game, hundreds of megabytes for opening books, tens or hundreds of gigabytes for endgame tablebases (6- or 7-piece respectively).

You would have to come up with a different chess game scoring system that doesn't take account of time.

Also, chess has no hidden state, so what would be benefit of using the zero-knowlegde system in the game?
15  Bitcoin / Mining / Re: Building Canada's Largest Bitcoin Mine on: September 12, 2016, 11:38:44 PM
If you read again what I wrote I said 'using a rectified supply asyou suggest' it's pretty clear I was referring to your 3 phase suggestion, so perhaps such a knowledgeable power electronics person such as yourself should not make presumptions before checking. Your idea of using a 3 phase rectified supply is fine in principle but I'm sure you realise the buck switchers present a highly inductive load, meaning PFC is necessary somewhere in the system to meet with most countries regulations and give reasonable efficiency.

I'm interested in what the GND guys make of your idea. I am not criticising the principle, just the practicalities.
The "rectified 3-phase power supply" cannot use single toroidal transformer and using 3 independent transformers doesn't make sense. The whole point of 3-phase systems is that they are conjoined triplets that provide savings approximately equal to division by square root of 3. The electric current going in by conductor X returns partially through the conductor Y and partially by Z. Same principle pertains to the magnetic fluxes in the lobes of the transformer.

PFC (power factor correction) is an issue pertaining to the AC systems. The DC systems have by definition power factor of 1. So the initial rectifier may have PF of less then one and require PFC. The buck converter may internally have PF less then one in their internal circuitry and PFC inside a buck converter will lower its conversion losses. But power factor does not somehow mysteriously transfer itself through the DC transmission system. That can only happen in the synchronous AC system.

There's a similar concept to power factor pertaining to the DC system: waveform shape factor (RMS(I)/Average(I)), but it is only pertaining to systems using certain physical phenomena like arcing (both intentional like arc welding and unintentional like lightning strikes). It really doesn't pertain to the coin mining where the load is nearly constant. It theoretically may be an issue in a regular computer where power used may vary eg. 10% - 100% depending on the CPU and disk load. This is why normal computer power supplies need to be regulated. The coin miner offers near constant 100% load. No regulation is required unless the power source is a battery or a solar panel. Moreover the coin miner gets momentarily under-powered this isn't any sort of "permanent failure", it is just a momentary increase of hardware error rate which is non-fatal.
16  Bitcoin / Mining / Re: Building Canada's Largest Bitcoin Mine on: September 12, 2016, 08:35:23 PM
No trolling intended. Obviously I'm not the kind of engineer that spend a few hours "maxwelling" it out while trying to determine the specs of a single cable, and I would hope you're not either. If anything, sorry for underestimating my public. And to be honest, I'd much rather engineer square pigs than spherical cows.  Cheesy

And I already mentioned that the pipes are used because of the magnetic fields.
Assuming you meant skin effect. While it is true that skin effect can be a factor, at the common 50-60 Hz frequencies that's rarely a consideration. You'd encounter it in some high voltage switching yards, but that's about it. After all, penetration depth at these frequencies is roughly a centimeter or two. And more still in iron, due to its higher resistance. For higher currents, solid copper bars are usually the way to go under these circumstances.

And when we are talking about low voltage DC distribution, skin effect isn't a factor at all.
So then by assuming you made an ass of u and me?

I never mentioned "skin effect", that was somebody else. With DC the magnetic field is constant. But because the conductor is near another conductor (carrying the current in the opposite direction) and near the steel/iron mechanical construction elements this magnetic field is very non-uniform. The non-uniformity causes gradients of the current density in the cross-section of the conductor. Therefore it is pointless to use solid conductors.

Once you realize that the conductor needs to be bulky, stiff and of considerable weight, the mechanical engineering steps in producing known mechanical solutions like pipe or I-beam. And then you realize that one conductor is at the ground potential and the other has non-deadly voltage that can be trivially isolated, then mechanical engineering steps even deeper: some portion of the weight of the whole construction and its mechanical load can be safely put on the conductor.

I wish I could give you a simple relevant Wikipedia, but I couldn't find pertaining directly. You may want to look at , although it doesn't directly pertains here. It mentions twelve-pulse bridge rectifier which shows what could be done without active regulation but with knowledge that we aren't limited to single-phase or even-three phase. There's also some limited discussion of what can be can be gained with dispensing with the grid-standard frequency 50 or 60 Hz.

I also tried to search via "data center dc power", but found mostly sales articles. And the coin mine is emphatically not a data center, primarily because it doesn't need uninterruptible power and because it is fairly trivial to reduce power usage by down-clocking when needed. But you may want to browse some to gain understanding of the modern technological trends made possible by extremely cheap power semiconductors.
17  Bitcoin / Mining / Re: Building Canada's Largest Bitcoin Mine on: September 12, 2016, 07:29:08 PM
The MAIN point, though, is that power DISTRIBUTION at low voltages for more than a couple feet is inefficient and expensive.
I disagree with you on the "MAIN point". In my opinion the main point is that the coin mine IS NOT a data center. It is an industrial power electrical/electronic facility. Trying to sell them as a low grade or low tier data centers is not going to be competitive, unless the business model involves coin mining only temporarily and switching to the regular datacenter work-loads/customers as soon as one could afford proper uninterruptible power and high bandwidth networking.

The coin mine requires data-center grade services only for the controllers and (low-bandwidth) networking, which amounts to probably around 1% of the total power budget. It think only Bitfury realized this in their product line and thus their requirement for large minimal purchases.

So if we want to give Great North Data props for something: they at least don't push UPS-es on the customers like several competitors few years ago.

The other main point could be: Bitcoin is too unstable to justify large capital investments (both financial and intellectual/human). There's no point in investing in Bitcoin without a clear backup plan (in case of GND: a regular commercial DATA center).
18  Bitcoin / Mining / Re: Building Canada's Largest Bitcoin Mine on: September 12, 2016, 07:03:07 PM
I have no idea if this is trolling, brain damage or bad schooling.  I'm going to guess trolling since you keep avoiding the question of what size conductor (wire, pipe, or otherwise) is needed for 100A DC power.  Or maybe given the way you like to refer to Maxwell's equations without actually using them, Morgan's maxim may apply here.
Yeez, dude, quit pretending to be stupid.

High-amperage distribution networks use stiff conductors, typically pipes or rails. Because of the strong magnetic fields involved they need to be designed to withstand several different forces and stresses:

1) thermal stress due to the resistive heating
2) mechanical stress due to the gravity and propagation of other mechanical load
3) magnetic force mechanical stress due to the current flow
4) while pure electrostatic stress is very low compared to the above the electric field requires consideration due to isolation safety, both due to breakdown voltage of the isolation medium as well as to possible contaminants: mechanical (like conductive dirt) or chemical (like humidity in the air)

Therefore nobody sane uses "size" as a single numerical parameter describing stiff conductors. There are computer programs to analyze and optimize particular configurations. There are also catalogs of standard pre-fabricated components used in high-current power distribution.

With regard to the computer programs: they all solve partial differential equations (PDE), typically using finite element method (FEM). On the electromagnetic side those are Maxwell's ones, on the mechanical side there's no single name attached because of the wide variety of mechanical models involved.

To summarize: stiff conductor is never like a "wire", they are never sold or bought according to a single numerical parameter like diameter (or gauge) for the "wire". Even in the "wire" category, when the mechanical stress is getting involved (like hanging wire) the "wires" are no longer sold using simply the wire gauge/diameter.
19  Bitcoin / Mining / Re: Building Canada's Largest Bitcoin Mine on: September 12, 2016, 04:59:00 PM
I have no idea if this is trolling, brain damage or bad schooling. I wouldn't be surprised that such a post was written by a code-certified electrical technician working on the sales side. I've meet such people that have the whole NEC memorized (including tables), but never heard of Maxwell's equations and can't solve first-semester student problems from field theory or circuit theory.

The classic example of unrealistically simplistic engineering is a "spherical cow in a vacuum". Here we have "circular conductor in the absence of a magnetic field."

And I already mentioned that the pipes are used because of the magnetic fields.

While it would take a BIG and very thick pipe to handle a 1000A load (which would only power 10 S9-class miners) with a reasonable I2R loss, the nice thing about steel pipes is that they are commonly available in VERY LARGE and thick sizes. I'm not sure it would be worth the savings on PS though to go with 12VDC distribution, but unless you design the miners specifically for higher-voltage "string" usage the efficiency loss of trying to string a few S9-type miners from a higher voltage supply would probably cost more than the savings from the higher voltage in distribution.
Going from 230VAC to 12VDC will increase the current with roughly 20x, and the required copper cross section to keep the same power loss 400x. So where at first you had a 6mm˛ (AWG 9) cross section of copper to handle the ~50A at 230V, that would turn into 2400mm˛ (AWG I can't even). With the current copper prices, that's a sizable increase in the cost of wiring.

Stringing the units together could definitely be interesting, however, if one develops a break the power on all units will fail. If one develops a short, the rest will, just like christmas lights, burn a bit brighter.

Also, DC doesn't suffer from "skin effect" all that much, that's much more an AC issue - but the pipes would still probably be lighter and definitely cheaper than trying to find something solid with the current capability required past a few hundred amps.
The difference in resistance between copper and iron, roughly a factor 6. So that increases the cross section from previous example to 14400mm˛, or if you rather, a solid iron bar with sides of 12cm (4 3/4 inch for the imperial inclined). Not exactly what I would call lightweight. Or cheap.
20  Bitcoin / Mining / Re: Building Canada's Largest Bitcoin Mine on: September 12, 2016, 04:46:55 PM
The big problem with using a rectified supply as you suggest is that the necessary step down transformer to get to 12v DC is going to be large, and hence expensive. A toroidal 1.6 kVA 230 - 9V example (enough to run an S9 after transformer and buck converter losses) would cost well over $140 in small quantities (less than 500) and you still have to add filter caps. It's not practical to have a distribution transformer taking 11kv or so to have a 9V winding so you have to take the voltage down to 230 and then uses a SMPS to get to 12. A prepackaged SMPS is likely to cost less to buy, will be a lot smaller, doesn't need assembly plus it will have PFC built in.
You seem to be making single-phase AC/DC calculations, while I (or any knowledgeable power electronics person) was discussing a three-phase system on the AC side. Actually AFAIK the modern semiconductor power distribution systems go into DC early and use multi-phase AC at frequencies higher than the grid's default 50/60Hz. For our application at hand there's absolutely no need to maintain the historical 60 Hz anywhere in the system.
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