Topic: [ANN] US/North American Bitfury sales NEW STOCK ***NOW SHIPPING*** - page 89. (Read 576772 times)

I've been authorized to offer bulk chips by the reel (3000 pcs) for $5/chip.  If you rate the chip at even 2GH/s this is only $2.50/GHs!

We are not taking deposits for these - this is an up-front payment required, no-cancel, no-return terms of sale.

Chips will be delivered in January 2014.

Cheers,
Dave

I want to clarify - we are not selling these 8 chip boards - no idea if we will be any time soon.

We are going to be able to ship some of the earlier queue October rig orders, but at this point I don't see us getting everything out before end of the month.  Assembling first rigs today & through the weekend for Monday shipping.  We just don't have enough product yet to do mass shipping.

I'll keep you posted on when the first big shipments go out from the factory to us.

The trim pots on the cards should be factory set to a safe level, but I've measured some differences from one board to the next.  I doubt the values could change due to shipping - you'll understand when you see how tiny the trimmer is.  Just cranking the thing to max voltage does not necessary produce more output - its careful tuning that will yield the best results.

Best,
Dave

i would guess that the regulator is half the size of a chip, but emits 3-4x the heat of a chip

Well poop... Doesn't look like we'll be hashing by Halloween with October orders

Yes, it gets quite hot. I believe they are also constructed do dissipate the heat to the board, but I did not do any research in that matter.
In my opinion the regulator heatsink is much more important than chip heatsinks.

Does this confirm you will indeed be shipping before the end of October? The 31st is next Thursday.

Very. I've put copper heatsinks behind the regulators - not directly because that space is blocked by other components. The heastsinks do get burning hot.

  you need to have fan cool down newer Hboards and it can burn out chips that why some people hboard got shut off by board get very hot.

Does the backside of the regulator even get hot? I have felt the top of the chip and its very hot but I don't feel much on the backside. Wouldn't putting a small heatsink on the chip do more?

For the hashing chips those thermal vias work well as even touching the vias themselves gets hot, even better with a heatsink.

noone has been running bitfury chips more than a few months, so its unknown

Sometimes graphite changes resistance after several hours of hashing in high temps. When voltages gets over 0.880 (measured between caps) on regular H-cards, they start to slow down. After 0.900V they slow down even further (5-15 ghs per card), until they shutdown completely. In my setup cards shutdown immediately when fired up over 0.950V. At one time I was able to measure 1.028V! The card shut down but after "repenciling" it got back to hashing as always :-)

Also there are differences between cards, I got one that runs ok. even at 0.930V.

I've got one 12 cards to experiment on. Second rig runs currently untouched.

EDIT: I have heatsinks on back of all boards in regulator area, and 120 CFM fans!

FTFY

We certainly don't want to connect an ohmmeter in that way!

Will you be selling any 8-chip boards? It'd be nice to eliminate the voltage regulator bottleneck on overclocking.

At what voltage would the chips be ruined if not actually mining and producing heat, such as with the chainminer process shut down? Is .895v where it just gets too hot, or where stuff starts shorting internally?

yup, they are pretty convenient and relatively cheap

If we don't have a multimeter or plain just don't know what we're doing, are we better off just getting gen 1 boards?  Does the trimmer have a zero stop so we don't accidentally plug the board in with the trimmer cranked up from shipping and handling?

I'm loving the gen 1 boards that arrived today (thanks for the quick shipping!).  They're hashing above 30GH/s with no OC.  I might be happier just filling up my old M board rather than working with a new starter kit.

do i see oshpark boards? I've been placing quite a few orders there lately

nice to see you guys selling 8 chips boards. FYI, for the one I made (https://bitcointalksearch.org/topic/m.3259455), I'm running around 0.9v and pulling 21-22GH and ~23W. been too lazy to try higher voltage.

How much of a reduction in life could I expect from my miner if I OC them up too a level like 40 GH per card or approximately 640 GH/s?  I'm planning to use heat sinks on all chips and have fans on them too.  Could I possibly hope to see something that lasts a year?

We are a couple days yet from getting our 16 chip boards with the trimmer on the board.  I have some 8 chip boards that are an experimental OC board that use the same trim pot and I want to set the stage for how this will work.

In order to use this trimmer, you *must* have a multimeter and know how to measure resistance.  If you don't know what I'm talking about, you aren't ready to try to OC your boards.

An easy place to take resistance measurements is to get ground off the M-board GND terminal (where you would connect direct 12V cables - the terminal screws).  The red probe would go on the top metal contact of the Pulse inductor, which is the large bulky component on the H-card.  Be sure not to also touch the caps that are nearby or you won't get a correct voltage.

While measuring the voltage, use your super-micro tweaker phillips screwdriver to *slowly* turn the trimmer clockwise for higher voltage or counter-clockwise for lower.  The trimmer has an effective range of about 180-degrees.  If you turn it down too far, you will see voltage begin to rise again. 

Don't make voltage changes quickly.  If you go higher than about .895v you better know what you are doing or you will kill your chips.  I don't even know what voltages people are getting away with on these boards.  Find a guide or post before you start mucking around.  Overclocking *will* reduce the reliability of the boards.

Graphite had negative temp coefficient or resistance, (temp, up, resistance down, vice versa). One way would be to make sure you have good airflow around the regulator, along with good heatsinks.

And if you do do that make sure to pick a resistor with the proper "temperature coefficient" - that is how the resistor value changes with temperature (which is pretty much what you've discovered here, although in your case there is an apparent "aging" of the pencil mod too - the carbon trace that you've added probably oxidizes and becomes more or less conductive).