Topic: ANTMINER S5: 1155GH(+OverClock Potential), In Stock $0.319/GH & 0.51W/GH - page 282. (Read 451048 times)

Tupsu, you seem to have a requirement to post only half of the story across many threads. The problem was caused by user error, as you can see here:

When I went to sleep they were "Up Coming" and when i woke up they were "Sold Out".

They are a nice little step up in efficiency but I didn't expect them to go so fast.

Today I bought 12 pieces Antminer S5

I trust them today more than SP20 , especially after seeing this picture. Because they have  4  PCI-E slot, For 600W.
SP20 has 4  PCI-E slot for 1200W (Max)


I have 3 x SP20 and
6pc SP20 purchased by December 17, to get my hands probably 29.12

I also have a 5pc KNC Neptune, with no burnt PCI-E slot.


The rest are all Bitmaintech production. (37x S3, 6x C1, 2x S4 )

It would be seen that picture before, then I would not have ordered more SP20.

sold out allready
glad I got my order in!

Will those who opted for L1 refunds in full bitcoin receive them soon? Will place an order if I get the refund.

Hard to tell from the pictures but according to multiple quotes by Bitmain in this thread, there are 30 chips per board.  15 steps, as you'll see if you look more closely (bottom left hiding in the shadows).

--
novak

Wow,

Thank you for paying detailed attention to our product photos!!!

There's 14 steps not 15. 0.64v at 9v.


If you look at the photos of the back there's level shifting.

I sat down one morning last week and worked up a rough design for relatively-low-bandwidth (maybe good for 1MHz, which should work for any practical miner's UART or SPI) logic level shifters and a constant-node-voltage current dump circuit which could, in theory, be used to chain any kind of chip with any arbitrary voltage. It's probably just a loose implementation of ASICMiner's proprietary PMS01 chip, which looks to be a pretty nifty device.
We're also contemplating working up a high-current (and hopefully high-efficient) inline regulator to make undervolting string miners easier off existing 12V PSUs. The basic design coincides with some other projects we're working on anyway. Something like that would be handy to strap some S5 (or Prismas) behind here in a few months.

I don't know if the S5 uses isolated or level-shifted comms, or some daisychain implementation like the Bitfury chips did. Haven't scrutinized the PCB photos enough yet to make an educated guess.

Also, the S5 has 15 steps in the chain (30 chips) so 9V would drop to an even 0.6V per node.

I didn't want to clog up this thread with these speculations, so i made a new

https://bitcointalksearch.org/topic/m.9922620

Took me an embarrassingly long time to work out where 9v is coming from. There's one chain per blade, two chips per voltage step in parallel for a total of 28, so each gets potential of 0.64v. I'd actually already begun thinking of how to do something insane like that, except I was going to replace the BeagleBong in each with some optoisolators on the SPI chains. Wouldn't be a massive undertaking to get 0.24W/GH out of the things but I don't know how much you'd be saving over the normal DC-DC, or more importantly if it would be worth it or not.

Love to get my hands on their chips and make a higher voltage blade, though I'm very inclined to think that they've bought Bitfury 3 masks.

Dang. I really hope he used an isolation transformer. That's a buttload of chips too.

Novak and I were chuckling earlier today, wondering how long it would take for someone to ground-isolate and stack three server PSUs, and stack four S5 in series to get 9V per machine. The only problem there will be ground loops on the ethernet cables causing your switches to explode, but it could be interesting nonetheless.

There's a post somewhere in the depths of the forums where someone got the Bitfury chips working straight from mains voltage in one huge string. I don't know how long it lasted, but I don't imagine it would have been particularly stable with the Bitfury's internal oscillator and the wildly swinging supply voltage. Absolutely lethal device with rectified mains voltages exposed everywhere, but impressive none the less.

This is the fourth string miner that I know of - the others being the OneString and Yazio (or whatever) boards with Bitfury chips, and the Prisma. I know plenty about how reliable the Prismas are, but not enough about the Bitfury-based boards. (A previous post mentions a fifth design I had not previously seen, so chalk that one up).

klondike_bar's assessment is not entirely correct; the active players in the circuit are voltage and also current. The capacitors at each string node will help balance out brief changes in current (which are natural occurrences with all the switching going on in the chips) to help maintain a constant node voltage, but won't really help much if one of the chips drops out entirely. Suddenly the current path at one node is cut in half, which means that, unless external provisions are made to compensate, the second chip in the node will have to push twice as much current as otherwise expected. This might result in the voltage across that node increasing until the chip is allowing that much current through, which will greatly increase the power dissipation (potentially quadrupling it) on that chip which very well might roast it. The best case would be the chip fails short, in which case you now have an unbroken current path, but with one of 15 nodes out, the rest of your chips' voltages increase by about 7%. If the chip fails open, you now have no current path and the entire board is down.
If, on the other hand, instead of the node voltage increasing until the current draw is in accordance with the rest of the two-chip banks, the current stays low and starves out the other banks, now you have a board which technically works but does not operate stably.
If each bank is provided with an active dummy impedance working alongside the capacitor, the two systems can effectively buffer the node voltages and chain currents to keep every chip functional. If one node's voltage starts to increase beyond what capacitor ripple can handle, this indicates it's not passing full system current and the dummy impedance can open up a bit to allow excess current through, keeping the system operating and the local node voltage at the expected value. If there's a stably controlled system like this in place, I'd have a lot fewer qualms about running one of these boards (we're actually toying with designing one of our own using that principle). I don't really trust unregulated strings as they are, but if there's some node-level regulation at least, it's certainly got more potential for stability and reliability than just trusting the chips to all operate within a narrow tolerance of "identically".

Another thing that's probably not something anyone wants to do, but could greatly assist the reliability of a chained design, is individually fused chips (alongside a controlled dummy impedance). If one fails short and overcurrents, the fuse blows and now that portion of the bank is an open circuit. Your dummy impedance will have to take its full share of the current, so with a chip like BM's where it's expected to draw around 9W you'll need a well-sinked dummy but that's not difficult. If an entire bank goes out, the dummy impedance will have to take the entire load, but it avoids the problem of overvolting the rest of the chain.

https://i.imgur.com/hAss6mY.jpg

Intron tried a stringed Bitfury design too. The problem is that they like to fail short, and when they do all of the others in the string get a proportionally higher voltage. Cascading failure and the magic smoke comes out, or magic black goop in the case of Bitfury's chips. I think they eventually got this one functioning under a slightly different design, but it makes me nervous all the same.

shouldn't

but...

does.

*cough* AM's Prisma chain design:

the fact that it was a


and you didn't open up sales, is a big red flag for me. You must have had problems that you wanted to hide?
why not just open up S3++ sales? I don't understand the logic here. It's not like you to remain so closely guarded.

what went wrong?

it's not the same ASIC, the community haven't tested the string design and I, for one just cannot take anything that dogie will offer us when he reviews, on the simple fact that you are paying him to do so. I have serious reservations about this miner.

s5 is a much riskier design due to the chain.. if one chip dies, the whole board goes down.
I've opted not to order now that I realise they have chained the chips.

If one chip fails it shouldn't affect the rest. The chip schematic has multiple Vin and Vout pins, and the only way to knock out the entire chain would be disrupting the voltage drop across chips. The s1 and the s3 both used chains for the data already, chaining power is the only new thing.