Topic: Feeding the antminer S3 with 3 pci-e cables? (Read 4869 times)

That helps alot. Thank you......

Your father-in-law told you that formula because it's a very important one.  Your home has a main panel with some level of electrical service (100A, 150A, 200A, etc) that you get from the power company.  You can't go over that amount.  Your dryer and your electric stove convert electricity into heat to dry your clothes, and to cook your food.  Now, take a look at that formula again.  Let's assume you have a 5000W dryer.  On 240V, to get that 5000W you would need to use just about 21A.  That same dryer on 120V would require 42A.  Remember, you've got a limit to your service.

I've simplified it and left a lot out, but in a nutshell, your typical home has the high-power appliances like central air, clothes dryers, electric stoves all running on 240V.  The rest of the stuff, like your lamps, televisions and computers run on 120V.

If we're going to consider bitcoin mining hardware, then you can see the difference with this example.  A typical household wall plug is connected to a 120V/15A circuit.  The 80% rule means that with a constant load, you can expect 80% of that 120V/15A to be available power.  In other words, 1440W (0.8 * 120 * 15).  An Antminer S3 needs 340W to give you 440GH/s.  That means, on this circuit I can run 4 miners.

Now let's take a look at that outlet the dryer is plugged into.  Chances are good it's a 240V/30A circuit.  Using the same formula, (0.8 * 240 * 30) we get 5760W.  You can run 16 Antminer S3s on that one circuit.

Make sense?

I was wondering about the 220/230 vs. 110/115. I ask my father n law about this and he always refers to that same formula. Why are appliances(dryers for example) always 220/230 rather than 110/115? Whats the advantage? It seems like a disadvantage as you would have to run a 220/230 circuit? Some have told me in the past that appliances run on the higher volts as this makes them more efficient. We just wired my trailer/mobile home with new circuits to avoid me burning the place down. We ran 110/115 runs. We also stepped up the incoming feed from a 100 amp main to a 200 amp main. Does this mean there is no advantage to running 220/230? Sorry if this seems dumb. I just dont get it.

What I mean by easier on electric is Use less, and what I mean by easier on heat is produce less heat/

Server PSU's are generally at least 80% efficient, and this 2000w one is 90+% at 50+% load.

not sure i fully understand your question about "easier on electric and/or heat" but things run more efficiently (ie lower overall watt usage) on higher voltage because they require lower amperage which means less of your electricity is converted to heat (due to resistance).  if you want to better understand this link may help (or may just confuse your more) - http://www.physicsforums.com/showthread.php?t=608751.

V (volts) x A (amps) = W (watts)

I have originally wondered about the server PSU possibility. I got a good deal on my rosewill lighning 1300 watt($139) and my Corsair's($49 for the 750 watt 80plus bronze) ($29 for 600 watt 80plus Bronze). The reason I didnt do the Server PSUs was I couldnt find the breakout board option for sale at the time and I couldnt find info on efficiency.

How is the efficiency of the Server PSUs as compared to the 80+ Bronze, Gold or Platinum ATX PSUs?

Also, is it any easier on electric and/or heat to run on 220/230 volts AC as opposed to 110/115?

How is that doing for you so far?

I plugged in 4 pci-e cable just so that each cable only need to supply less then 100 watt.

Gotcha.  Thanks for the clarification

the dell 750w PS's come with fans.  the 1st version of gekkoscience's breakout boards did not have fan controls so the PS's fan ran at 100% always.  the 2nd version of the board allowed you to control the fan speed.

the 2000w PS's do not have internal fans, so yes you need to keep them cool somehow.  the box fan does an adequate job, but is definitely not the most effective/efficient way to do it (that picture is a better example of how to do it).

Oh... I thought the server PSU came with fans... people always complained about how loud they are because of the fans.  If they don't, then I certainly see the need for moving air over the internals.

If I read the listing correctly, the PSU doesn't have it's own fan.  It was likely designed to be cooled by the server's fans.  So, you'll need something.

Here's what one person did.  Seems reasonable, just looks like shit.

https://i.imgur.com/tyn5r7l.jpg

Out of curiosity, why use the box fan, other than to just move the hot exhaust away?  The PSU itself has fans to keep its internals cool, and the S3 has its own fans as well.  Are you saying the PSU gets so hot, even with its own fan, that you need the extra box fan to keep it cool?

i just have a box fan that i use to move air across it and push the stagnant heat to the other side of the room and it seems to keep cool enough.

no soldering needed.  the board that interfaces with the power supply plugs right in and has an on/off switch and the power is distributed through screw-down terminals.  the cables they provide with the unit are the U-type clips that slide in and you screw down.

How do you keep it cool? And does it require some soldering?

well i hesitate to call them morons or ignorant, but probably the latter.  they either dont realize these products are out there or feel they are not as safe.  or possibly the fact that they are pretty much targeted for this purpose only makes them harder to resell or reuse in a gaming rig later.  gekkoscience's latest product can run 5x S3's - http://minersource.net/products/delta-dps2000w-with-adapter-board - with even some room for overclocking.  you just have to make sure you keep it cool and have 220/240v power.

yes looks like much cheaper solution. My question is why everyone is using ATX PSUs then?

the power usage is separate per side so the 3rd cable would just help distribute the power load on that one side.  i'm not affiliated with minersource (http://minersource.net/products/dell-750w-psu-slash-adapter) or gekkoscience (http://www.gekkoscience.com/products/D750_supply_breakout_board.html) at all but i've purchased several of these products and they are prob the best use of your $ if you are going to run S1's, S3's, BTC Gardens, etc.

I run 2 S3's using a Corsair CX750M.  2 pci to each miner.  Runs well.  Hope it helps.

I've only skimmed through this thread but thought I should point out I've had PSUs which before now will shut down if there is no draw on the +5v and +3v rails... to remedy this I just plugged in an old CDROM drive.

OK, good .  Now that we've cleared up you're plugging things in properly, I fall back to my original post here: I wouldn't trust the PSU.  If you're plugging in only 2 PCI-e cables and it trips the PSU, something's off.  It looks like you tried another PSU that exhibited the same behavior at first, but has since run properly?  What kind of PSUs are you using?  I've got EVGA 1300 G2, Corsair HX1050 and a Corsair CX600M that I use and have not run into issues like you're describing.

OK... another question for you that may seem obvious: are you accidentally causing this on your PSU somehow (like, are you using the old paperclip test, and that clip slips out or shorts or something)?

Crypto, to be honest TT units aren't the best so 150+W per rail may be much for em; I run Seasonics and they couldn't care less, 150W per wire is just fine, but id be weary of doing that on lesser quality units
if you do have the 4 wires, why not plug em all in ? if you don't have 4 wires, use adapters from molex to make 4 wires

yes, for sure

This may be pointing out the obvious, and at the risk of insulting your intelligence, you did plug a cable into each board, and not two on the same one, right?

In other words, you plugged in like the green ovals, and NOT like the red rectangles:

I added Startech PCIe splitters to each PCIe cord. It works fine on EVGA1300 and cords are not even hot when at 237.5mhz.
Naturally, both ends shall go to power the SAME board.

The 6-pin is differentiated from the 8-pin by only 2 ground wires.  If the PSU is single rail and uses quality cabling it shouldn't be an issue, especially if you use 3 or 4 cables.

First, drawing 180W through a 6pin is dangerous and I wouldn't recommend it to anyone.

You might be activating some sort of protection on the PSU (they are very safe and programmed to shut down immediately when things get too hot or overloaded), so the best test would be just to plug in the 3 PCI-e cables and see how things go.

Good luck!

Not sure if this will help. I'm using a gold rated single rail 1000w PSU for two S3's. If i plug the PCI-E's into a miner the fans blow but it doesn't boot. I have to use 3 PCI-E in each miner. Not sure if this is just the modular PCI-E cable. Didn't really bother checking.

I tried with another  800W single rail PSU and it did the same first time,  but working for few hours fine now.
However if it does it again, I guess I'll just try with 4 pci-e cables plugged.
So, we know for sure that plugging 4 cables splits the load evenly between them all?

I would agree with the earlier posts on a possible power supply issue. I'd also look at what your power supply is plugged into. I recently had an APC PDU acting up and once I replaced it, my S3's became stable.

That should be plenty of power for a single S3.  It is possible the PSU protection unit is bad, or something else about the PSU has failed.

it's a single rail 630W  thermal take one and it gives 588W to the PCI-e connectors
so should be more than enough, that's why I thought it's the cables, but what you say about them first getting hot makes sense.
Can there be some protection built in that does that?

the AC outlet should have plenty to supply them I believe, there is nothing else on it.

So, what else it might be?

If you have extra pci-e cable you should just plug in all 4. Having 90W on each pci-e is always better then 180W.

If the PSU is shutting down, either it is overloaded, or one rail of a multi-rail PSU is overloaded, or your AC outlet is not supplying enough power for the PSU.  If the cables are overloaded, it will cause them to get hot, but that alone should not cause the PSU to shut down until the insulation melts, and the cables short out.  

If plugging in a third cable helps you, then maybe the first two cables are on one rail and the last cable is on the other?  Try to make sure each blade of the S3 is on a separate rail if you can.

All that being said, it will not hurt anything, and can only help to plug in PCIe cables to the extra slots on the S3, whether you are over clocking or not.

At stock speeds the S3 pulls 340W from the wall, meaning it will pull less from the PSU itself depending on efficiency.  What PSU are you using that keeps shutting down?  I don't know that I'd trust it .  How many rails does it have?  Can it supply enough juice (watts/amps) to the PCI-e?

Bitmain has recommended connecting 4 if you're over clocking, or 2 if running stock.  There's nothing that says connecting 2 on 1 blade and 1 on the other will work.  Even if it did work as you hope, then you'd have 170W draw on 1 cable and 85W draw each on the other 2 (assuming the 340W power requirement).

The PSU seems to shut down when feeding it with just 2. It might be because the cables are made for just 75W and it pulls 180W through each (so it drains 360W in total).
So, I'm thinking can I plug a 3rd pci-e cable, without overclocking it just to spread the power a bit more, or it doesn't work like this?