Well it depends.  No device is fine at 99.99999C and then explodes at 100C.  The hotter a component gets the less efficient it becomes that means more current is needed and more current means more heat which means higher temps, which means lower efficiency .... and the cycle goes on. 

All the problems seem to be limited to the rushed "lets cut the number of VRMs in half" mid production modification version.  If the 4 VRM version (doing the job of 8 VRM as designed) is running at high load then even a modest amount of cooling could improve performance.  Not saying that IS the case just pointing out it could be.

Agreed.  Either he is misunderstanding (playing a game of telephone here) or it is just nonsense to shift the blame.

Power suplies don't ramp up current.
Power supplies don't force current.
A circuit DRAWS current.
If the circuit was damaged by drawing too much current then the circuit shouldn't draw so much current.

Now you are just going round and round in circles.  A miner isn't normally unplugged either.  However both a routinely are connected and disconnected over the lifecycle of the device and a powersupply needs to handle that.  It is the sole purpose of a regulated power supply.  It is what they get paid to do.

If the scenario that disconnecting and reconnecting a mining board would allow overvoltage to occur the same would happen when disconnecting and connecting any powered device.  People do upgrade computers you know.   If the bogus scenario you believe was true then a high portion of motherboard upgrades would result in destroyed motherboards.  Of course that doesn't happen because power supplies are designed to regulate the voltage.  The power supply has both a power-on and power-good signal.  I doesn't energize the output rails until it verifies the voltage is regulated.   There never is a scenario where a power supply lacks an active circuit.  It has control of the input power and the ability to power internal circuits for the sole purpose of continually monitoring and regulating the power output.

The jumper isn't signalling a motherboard is connected it is signalling the power supply should supply power to the rails.

Overvoltage into a motherboard is just as bad as overvoltage into any other device.  You are replacing one device which will be destroyed by overvoltage with another device which will be destroyed by overvoltage.  Motherboards contain filtering capacitors on their input voltage leads, just like mining boards do, just like GPU do, just like just about every electronic device ever made does.

Any regulating powersupply is designed to do exactly that.  The sole purpose of the power supply is to ensure that the output remains within a range (usually <3%) around 12V nominal.  Please show me in the ATX power spec where a power supply is suppose to shunt overvoltage into the ATX connector.  Please show me in the ATX spec where a motherboard (a device vulernable to overvoltage) is designed to be the dump for excessively high voltage.

It is complete and utter nonsense.  No power supply is designed to dump dangerous overvoltage into the ATX connector to let the motherboard "handle it".  What would be the point?  The POWER SUPPLY is the place to regulate voltage.  If there is excessive voltage it is the responsibility of the powersupply to either regulate it or disconnect the load (connected devices).   Yes power supplies contain overvoltage, overcurrent, and overheat protection circuits.   The powersupply (not the motherboard) monitors the voltage, current, and its internal temp and the powersupply not the motherboard kill the current if it is out of spec.     If the motherboard was going to regulate the voltage then there would be no need for a power supply you could just connect your power cable directly into the motherboard.

Oh that would be funny if it wasn't so naive.

Your govt doesn't issue money.  Your central bank does which is a private cartel of banks who has been given a monopoly on issuing currency.  When they issue currency they and only they benefit.  They benefit because more issuance means more inflation but inflation is a lagging effect and so the money they issue today won't have its purchasing power degraded until after they spend it.  You on the other hand well you get your money slowly after it has filtered through many layers from the banks on downward so the prices have already adjusted.  Ever notice that you get a 3% raise (not a promotion but an annual raise) but by the time you get the raise prices have already increase 3% (or more).   You never catch up.


Governments build schools and roads and healthcare (and bombs, and engage in terrorism, and build police states, and incarecerate people) using TAX REVENUE which has absolutely nothing to do with the issuance of currency.  There are many countries which don't issue their own currency.  Belize for example defacto uses the US dollar as their national currency.  How does belize build roads?  Simple people pay taxes (often in US dollars) and the government spends those to build roads.

Governments have no money.  Governments don't build roads.  Governments collect wealth (through the us of force) from citizens in the form of taxes and pay for goods and services just like you or I do ... by spending money.

Citizen (wealth) ----> Government ----->  Road Builder

The only difference between you hiring someone to pave your driveway and the government hiring someone to pave a highway is the first involves voluntary free exchange (you give some money and the paver gives you some driveway) and the later involves the use of force (monopoly on violence).


As for no longer owning Bitcoins, well it sounds like it is a source of stress for you and life is too short for all that.  You may have made the right decision for you.   However even if you never use anything other than "national" currency you might want to do some research on what money is and how it doesn't work they way you think it does.

One thing I would point out is that batch 1 is a single design single board per unit only and was limited to 500 units.  So the difference between first and last isn't quite the same as being the difference between the first and last BFL order.

I have no idea if HF can meet their deadline.  No company to date has.   The closest would probably by Bitfury (US distributor) with only a 3-4 day delay for all batch 1 orders and the worst is BFL with a 6-9 month delay.   That being said assuming they have competent production and can move out 100 to 150 units a day (pretty conservative) the timeframe from first unit to last unit would be 3 to 5 days.




What concrete fact are you looking for.  I have found if you ask a specific direct question the HF staff will generally respond (although it can take a couple days).  Vague questions like give us your entire supply chain are likely not going to get answered.

It is fine.  Technically it is pin 17 (pin 4 is the one on the first row).  The "power on" pin just needs to be "pulled low" and that is done by connecting it to the ground.  Any ATX ground pin would work fine.

http://www.mupuf.org/images/wt-rpm/connector_atx_pinout.gif

Hell connecting pin 4 to the power supply screw will also work (the chassis of the power supply is grounded).   How this is done paperclip, adapter, PSU tester, custom power board (Avalon), custom built power switch, motherboard, etc.  It doesn't really matter.

Pin 4 is "high" = not connected to ground --> power supply is "off"*
Pin 4 is "low" = connected to ground (any ground) ---> power supply is "on"*

* Technically off/on is poor terms because even when a PSU is "off" it is powered internally and supplies power to the 5VSB rail.  When a power supply is "on" it can be overridden by internal logic and output power shutoff due to overvolt, overcurrent, overheat, or other internal fault situation.

There is no need for a motherboard to be connected.   The power supply turns on the when voltage on that pin is low and it turns off when the voltage on that pin is high.  A motherboard, switch, or paperclip all do the same thing they connect the power-on pin to ground which pulls the voltage low.  When the power supply is on (plugged in and any hardwired power switch is turned on) it monitors that pin and supplies continual power to the 5VSB rail.  When it goes low it "turns on" = supplies power to the other rails, and when it goes high it "turns off" = disconnects power to the other rails.

Yeah not only is it low current it is also low voltage, about 0.9V and 500mA.  You have more risk of electrocution handling a AA battery without protective gear.

While it only takes about 300mA of DC current (only 60 or so mA for AC current) to cause irreversible ventricular fibrillation. The good news is the human body is a pretty good resistor and it takes a pretty high voltage to the protective insulator we call skin.  If it wasn't then people would just be killing each other on a daily basis with static electricity shocks. 

Anything below 50V isn't a significant shock risk unless you somehow managed to stab both ends of the paper clip into your heat cavity while still being energized.  Then again if someone can manage to accidentally do that they probably are doomed anyways.

What happen to margins on margins.  The boards were designed to have 320A of DC regulators (which drop the 12V supply down to the 0.75V used by the chip).  Now if BFL cheaped out I could see that but KNC has talked for months and months and month about margins on margins so when they actually get to the finish line and start shipping products at the very last minute they decide to yank out all the margins and run the hardware at close to the theoretical limit and hope everything works.  

So the solution to an overheating and overloaded power system is to push the power system even harder.  To take 160A (which was designed to be 320A) of capacity and run it at 25% over the redline.  

So what is is this negative margins on negative margins now?


How about just start shipping the proper 8 VRM design and offer replacements to affected customers (who you shipped underperforming units).


Yeah that seems like the solution.  Open case, giant fan, hardware running overspec, and power consumption through the roof.  Throw in the cost of high AC load to maintain 20 deg C cooling.  Too bad there is no simpler solution like I don't know ...shipping the product as designed, promised, and sold.


So wouldn't the best solution to ship the boards with 8 VRMS as you initially promised they would?

Yeah I have turned PC off GPU rigs at the switch a couple thousand times.  It is a non-issue.  There is a reason open frame GPU miners used power supplies with a physical power switch on back.  The theory that it powering off highly regulated UL listed ATX power supply destroyed connected equipment doesn't hold water.

There are ~300 million PC in the US.  If yanking the power would blow up a motherboard 1% of the time and the average PC experiences 3 blackouts a year then you would be talking something on the order of 9 million destroyed PC every single year.   Say average PC is $500.  We are talking about a half a billion dollars.   If it genuinely was a problem then PC mother boards (and GPU and other hardware) would come with circuit breakers or at least a $0.20 quick burn fuse.  Of course they don't ... because it isn't a problem. 

What measurement?  You posted a bunch of nonsense not a measurement.

A Jupiter can't use 1200W.  The DC regulators are only good for 320A max (and running them at max current 24/7/365 is a good way to destroy them).  So lets assume 80% duty cycle.  320A * 0.75V * 80% = ~200W per board or 800W total.   Throw in another <50W for fan & controller and you are looking at 850W peak.  Note I am not even sure the chip can use or handle that kind of power but even if it could the DC regulators on the board can't provide more than that.

Before buying a second PSU and a 1600W "bonus", have you spend $20 on a kill-a-watt to see what kind of power you are pulling from the wall? If you are pulling 500W from the wall then buying 850W + 1600W to supplement your existing 1600W to power the same sub 500W load is going to do absolutely nothing expect waste money.

In the first photo the upper left hashing board is it just a camera trick or is one of the heatsink mounting screws missing?

Potato tech maybe.  (Just kidding).

Simple version is no.

The quotes refers to the inrush on the AC side of a power supply.  It is taking about how much peak current the power supply will pull from the outlet when it is plugged in.  Simplifying somewhat a power supply has lots of beefy capacitors and those capacitors can charge very quickly resulting a very high power draw (even if the PSU isn't connected to any load).    A good PSU will limit the inrush by "slowing down" the charging of the capacitor bank.  A poor one won't and that could (depending on what else is on the AC branch circuit and breaker limit) exceed the limit for the circuit and cause the breaker to trip.  Still all that has to do with the AC side of the circuit.

I don't know how or why the KNC miner in question was destroyed however the explanation that a power supply "forced" too much power into it is well nonsense and violates basic electrical theory. A circuit (any circuit) "pulls" current.  A power supply isn't going to "delivery" any more current then is pulled by the circuit.  It is up to the circuit/device to ensure it doesn't pull too much.  A 1200W PSU doesn't mean it forces 1200W into every circuit it is connected to it simply means the power supply can deliver up to 1200W.   Just like a "regular outlet" is 15A that is 1800W max but if you connect a lamp with a 23W light bulb the outlet doesn't "force" 1800W into the lamp exploding it.

Ouch That is brutal.  I would be freaking out so here is some help.  The coolers are off the shelf Artic Cooling A320 CPU coolers.  Looks like the fan portion simply "snaps" on to the heatsink main body.  Take a look at the unboxing video and other install info in the link below.
http://www.arctic.ac/en/p/cooling/cpu/473/freezer-a30.html?c=2181





In a related note for people who want more airflow it looks like the cooler can be expanded to a second fan on the other side (push pull config).

What power supply are you using?  What is your mains (outlet) voltage? 
I assume the 482.7W is measured at the wall (kill-a-watt meter or equivalent).  From the web interface there should be a way to see the DC power used can you see how that compares to the 482.7W?

This.  Asset forfeiture isn't something new or novel.  The fact that it involves Bitcoins might be but there are long established procedures for forfeiture. The DOJ seizes all kinds of assets, vaults of gold, stocks, stock and bank accounts even warehouses (literally warehouses) of cash.  Then there are the mansions, yachts, jets (hell even giant cargo jets), cars, luxury watches, etc.  Every once and a while a drug bust turns up some rare painting or other work of art.

It all gets EVENTUALLY sold at auction.  However until convicted the assets are the property of the original owner.  Once there is a conviction the DOJ will file for forfeiture.  Simple version is the govt says "this is the proceeds of a criminal enterprise as we are taking ownership".  That legal battle may take months to YEARS and only starts months or years AFTER a verdict in the original court case.

For those thinking the FBI sold the coins on MtGox overnight.  Imagine the small but not zero chance that the SR operator is found innocent.  His lawyers first action would to file for a court order demanding the return of his clients unlawfully seized property.  If the FBI already sold something which wasn't theirs and the price in the meantime trippled .... ouch.

The wheels of justice are amazingly slow.  Those thinking this will be resolved in days or weeks will be disappointed.   We might be talking in 2014 or 2015 about a public notice filed because the DOJ is looking to sell some Bitcoins.

This.  For Bitcoin mining all that matters is 12V power.  Also even for modern computers 90%+ of high load systems is going to be on the 12V rail.   Simple version is that "trusty" Antec 850 is a piece of junk.   Low efficiency, multiple small rails, 3.3V and 5V are directly rectified (means there is a min load to avoid unbalancing).  Most quality modern supplies use a single high efficiency rectification from AC to 12V and then do direct DC conversion for the ancillary voltages.  I would ebay it to someone who doesn't know any better.