Antminer S7 Dell 750w Server Psu Question

[Shizz152]

So i bought an Antminer S7 and was planning to use two dell 750w server psu's with the gekkoscience breakout boards. I had planned on using two in load balancing mode using a signal wire and two current sharing wires, one positive, one Negative. This is shown here: http://www.gekkoscience.com/products/D750_3way.html



Anyways is this setup possible with an Antminer S7? The first thing it says when opening the box is not to use anything lower than 800w if your using one psu for two hashing boards.
So will using the above gekkoscience setup totaling 1500w work with two psu's in load balancing mode? If the psu that powers two boards needs more power will it take it from the other psu? Just want to make sure this is safe. I haven't seen much talk about this setup since the S7 came out.

I am running a Batch 4 4.66 th/s

UPDATE:

I Set it up and prayed that nothing would break. I am sad to say it did not work like a 1500w psu and allow the S7 to run! This was very surprising result. Luckily the S7 is still fine and up and hashing.  The psu cut out currently. So Bitmain was right. If you buy an S7 you must have no less than 400w per board. So 800w for two boards. This is unfortunate as i do not want to buy another noisy psu and another breakout board.

Useful INFO about S7 setups:

After I restored my setup with 3 psu I tried to make the two dell server psu quieter by using a single pin wire and grounding the fan pin on a gnd pin. After i started the system up it seemed a tad bit quieter but it was hard to focus as i was scared of something going wrong. And then the HW Errors went over 8%! i immediately shut the system down out of panic, and it is running nice and noisy after scraping that idea.

Also I was running fan speed at normal because i wanted system to run nice and cool with the winter air intake. After changing the fan speed to a sweet spot of 50% (3570rpm front and little less rear). The system warmed up to between 48-52 on chips and the HW ERROR went from 1+% to .0064! Antminer S7 has a sweet spot temp! Hashing is more steady to now.

BTW Antminer S7 @ Fan 50%, This is about the point where you here the dell high pitch psu thats how loud they are under load!

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[Prelude]

Perfectly fine. I'm using a similar setup. 2x DPS2000 PSUs load sharing to power 3x S7s.

[RichBC]

With the 12V & Gnd strapped and the current share line connected you have effectively created a single 1500W PSU and there is no need to worry about how much power is coming from each of the individual PSU's.

Rich

[Shizz152]

I Set it up and prayed that nothing would break. I am sad to say it did not work like a 1500w psu and allow the S7 to run! This was very surprising result. Luckily the S7 is still fine and up and hashing.  The psu cut out currently. So Bitmain was right. If you buy an S7 you must have no less than 400w per board. So 800w for two boards. This is unfortunate as i do not want to buy another noisy psu and another breakout board.

Useful INFO about S7 setups:

After I restored my setup with 3 psu I tried to make the two dell server psu quieter by using a single pin wire and grounding the fan pin on a gnd pin. After i started the system up it seemed a tad bit quieter but it was hard to focus as i was scared of something going wrong. And then the HW Errors went over 8%! i immediately shut the system down out of panic, and it is running nice and noisy after scraping that idea.

Also I was running fan speed at normal because i wanted system to run nice and cool with the winter air intake. After changing the fan speed to a sweet spot of 50% (3570rpm front and little less rear). The system warmed up to between 48-52 on chips and the HW ERROR went from 1+% to .0064! Antminer S7 has a sweet spot temp! Hashing is more steady to now.

BTW Antminer S7 @ Fan 50%, This is about the point where you here the dell high pitch psu thats how loud they are under load!

[Shizz152]

Perfectly fine. I'm using a similar setup. 2x DPS2000 PSUs load sharing to power 3x S7s.

What Batch S7 do you have? And also How is the hashing board power connection setup for the S7 that shares the two power supply's? With 2000w you can have one s7 and then 800w for the two hashing boards on the other S7. I think that is what allows yours to work so well. Also Your on 240v I am assuming? I am using 120v that's also a limiting factor on these supplies. I've herd with 2000w and up  server psus rated at  80 plus platnum can do at least 10% over spec to.

I think the current sharing is more for any imbalances or spikes in power to keep efficiency up. I don't think it means it can pull more than the rated spec of the psu sustained. At least not for the 750w Dell and breakout board.

[RichBC]

I think the current sharing is more for any imbalances or spikes in power to keep efficiency up. I don't think it means it can pull more than the rated spec of the psu sustained. At least not for the 750w Dell and breakout board.

Did you connect as shown in the link you provided, with the Power & Ground strapped together and the current share line connected? If so this does create an equivalent of a 1500W PSU by ensuring that each of the 750W PSU's is equally loaded up to the 1500W maximum. This is intended for a full time load not just spikes etc.

If it was connected correctly then there must be a fault in the load sharing of your PSU's


Rich

[Prelude]

How were you pulling power from them? You must've made a mistake or omitted something somewhere. Here's what my setup looks like, yours should be very similar:







You made a bus bar for 12V and ground, right? Something like the 2 copper strips in my picture? Those are what you need to pull the power from, your PCI-e wires should be connected directly to one or both of the PSUs.

[Shizz152]

How were you pulling power from them? You must've made a mistake or omitted something somewhere. Here's what my setup looks like, yours should be very similar:

http://s21.postimg.org/i14qn4io7/20151205_204003_Copy.jpg

http://s21.postimg.org/t1zvs5ax3/20151206_034606_Copy.jpg

http://s21.postimg.org/pslglomtj/20151206_043944_Copy2.jpg

You made a bus bar for 12V and ground, right? Something like the 2 copper strips in my picture? Those are what you need to pull the power from, your PCI-e wires should be connected directly to one or both of the PSUs.

I Did not create a Bus bar. I tried only with the boards. I had to put two wires on one screw. I had to invert one connector to do that as well. So you think just not having a bus bar would be what was causing me problems with my current share and distribution?

[RichBC]

How were you pulling power from them? You must've made a mistake or omitted something somewhere. Here's what my setup looks like, yours should be very similar:

You made a bus bar for 12V and ground, right? Something like the 2 copper strips in my picture? Those are what you need to pull the power from, your PCI-e wires should be connected directly to one or both of the PSUs.

I Did not create a Bus bar. I tried only with the boards. I had to put two wires on one screw. I had to invert one connector to do that as well. So you think just not having a bus bar would be what was causing me problems with my current share and distribution?

That way of Bussing will be fine, so long as the gauge of wire is sufficient. Did you connect the current share line? Do you have a picture of your setup?

Rich

[Shizz152]

How were you pulling power from them? You must've made a mistake or omitted something somewhere. Here's what my setup looks like, yours should be very similar:

You made a bus bar for 12V and ground, right? Something like the 2 copper strips in my picture? Those are what you need to pull the power from, your PCI-e wires should be connected directly to one or both of the PSUs.

I Did not create a Bus bar. I tried only with the boards. I had to put two wires on one screw. I had to invert one connector to do that as well. So you think just not having a bus bar would be what was causing me problems with my current share and distribution?

That way of Bussing will be fine, so long as the gauge of wire is sufficient. Did you connect the current share line? Do you have a picture of your setup?

Rich

I am working on using a different dell PSU to use for two of the hashing boards on the S7. I have to many connections to be using only 2 psu w/bob. I do need some help though. I need to take 6pin pcie cables and attach them to a single 14 awg wire. I need to attach two pcie 6 pin for one 14 awg wire. Example, So 6 individual positive pcie cables have to connect to one 14 awg wire. How do i do this? Do i need to  tie connections together, solder and tape? Or do i need to use crimp? I see your pcie loom changes sizes where the electrical tape is. Did you change wire gauge twice before pcie 6 pins? I need a little push on how to attach multiple different gauge wires.  Other than that i have the connections for the psu to 14 awg wire. Can you help me?