Bitcoin Forum

Just got a simple question regarding running S7 units as considering to buy one.

As the unit does not come with a PSU can I run 2x 750w power supply and have 1 power supply connected to each blade to provide 750w on each blade using 2x corsair gold rated psu Will this provide enough juce as will total 1500w for the unit? or am I best just grabbing APW3-12-1600-B2 to power it up?

Although I don't have a first hand experience on this matter, You could connect different PSU's as long as their connected to different hashing boards with out a problem but why would you complicate the situation when you could just use what Bitmain itself has recommended APW3-12-1600-B2 plus it has more limit as opposed to using those two power supplies together.

I always have went the easy route and went with the bitmain server.   If I was going to go with anything else it would be another server PSU from some of the kits around here on PSU's.  

I know some mix it, and it should work with exact same one I just don't like it.   One blade with a 750 I would think would have two separate PSU's on it, which I'm not huge fan of and bitmain does not recommend.  Will it work.... chances are yes since same PSU.   But killing your warranty, which is a shame. 

Here is the wording that mixing would void warranty:
2.   PSU: A power supply unit is not included, and you will need to provide an ATX PSU. There are 3 PCI-e connectors for +12V DC input on each hashing board and all 3 are required. Do not connect more than one PSU to the same hashing board!

Also, the s7 has 3 blades with 3 PCIe inputs on each for 9 total needed for the blades.  Plus one more for the controller/IO board combo (not powered by the blades as the s5 was...)

I bought a lepa 1600W unit.  It does have 6 output plugs for the 4 30A 12V rails, but as long as you watch what's going where so you don't overload one of the rails it _should_ be all right.  I say should since I've UC'd by s7 by about 25% to keep from running up the electrical too much, at the cost of total hash, I know, but it should be even more efficient than .25W/GHs.

Need to measure that one of these days...!  ;D

As written above:

In the rest you can fool around as much as you like for s7:
2miners on 1 psu
1miner on 1 psu 1600watt
1miner on 2 psu, one above 1.1k and the other 600watt
1miner on 3 psu, all 600watt

It also depends on the batch of the s7. On first batches the evga 1300w is good enough!

That is the problem is it is going to void warranty which is a shame in a lot of cases.  Two 750's are mentioned so 1 is not going to be able to power 2 hashing boards.  So it would be mixed and voiding warranty.

I thinks it kinda get's into a mess connecting multiple.  If it's in your budget I would get a decent server PSU, and use it.  Chances are I don't see bitmain moving away from 10 PCIe, as it has made them money selling PSU's. 

So you likely will be able to use these server PSU's more then 1 generation still.  And if not can always sell after. 

got 4 psu on an ''c2'', same thing goes for an sp20 of mine ;D

server psu is the best: efficient and cheap!

Looks like I will just buy the psu from them or get something local with the same outputs for it if I decided to go down the road of buying some s7s but am 50/50 again after seeing prices all over the place diff all over too and with the ever growing halving am like hmm

I think the PSU's will remain to be valuable on thiers.  I think they get a LOT of extra sells off PSU's by using the 10 PCIe connectors.  So as a company I think Bitmain is going to stick with it.   And I could be wrong on that.

As a company it was a smart move.  Kinda stinks as customer that there just are not a ton of 10 PCIe psu's in ATX without going very expensive.  But server PSU's have kinda taken over anymore.  I don't think you will regreat the psu as long as you have the 205+ volts to start it.  The miner.... we will know more after a few weeks of seeing what difficulty does and BTC value.

Actually Bitmain says "you can use two X watts atx psu to power this no problems" so why would it void warranty? And i don't really get why you repeat all the time most ATX psu's dont come with 10 connectors.

Server psu's outside packages actually don't come with cables at all either and its not a problem. You can just get the cables or connectors you need elsewhere.

Then if you buy two ATX PSU for 70$, you will have plenty of connectors. If you go for something like an EVGA g2 1300w, well it comes with 8 PCI-e, so you will need two splitter, which you can get on this forum for 3.5$ each.

http://www.evga.com/products/Product.aspx?pn=120-G2-1300-XR

It doesn't get 93% efficiency like the Bitmain PSU at 99-100% load, but it works. (1460w~1480w~ depending your fan speed for a B8)

Did you read the post dealing with warranty? You might read it again as I think your talking about different PSU's then the ones mentioned in that post and what OP mentioned in original post.


He mentions using 2 - 750 PSU's.  If you did that you would be mixing PSU on one blade.   Which is very accurate.    I don't get why your looking for a issue it seems like from post not sure why.

I'm not debating that you can get cables or a EVGA 1300 is a good psu I have multiple of it and yes it is nice PSU but it's also 180 dollars on amazon.  So instead of that I normally recommend server PSU's which normally are cheaper.   And the bitmain PSU is a good psu I have had no issues with it either so I don't have a problem recommending it with a S7.

I find him a bit of a bundle of negatives... hope i said it well as english is not my 1st language ;)

Do not mix power supplies on the same blade!

I'm talking about 2 blade one one 750w PSU, here. There must of been some confusion, in my intent. I'm not saying to use two 750w on any one blade. I guess what you two read from OP is. "Can i put 1.5 blade per 750W"? Answer is indeed no. You'd need a 850W-1050W PSU and a 650W+ PSU ideally.

You'd have to do 2 blades on 1 and 1 blade + controller on the other 1. Would be pretty rough to do this on a B8, you'd likely have to underclock
to clear 50-60w on PSU 1. I doubt the Corsairs are as badass for running the PSU overloaded even by a little.

And also that the EVGA g2 1300 is also okay for B8. But i acknowledge it would be better for earlier batches since for a B8 you get pretty much 0 headroom.