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)?