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I've been working on something since april or may, it evolved with the S5+, and another time with the announcement of the S7.

Since pictures may speak better than words, here are some first shots of the prototype:

https://i.imgur.com/IBuAtYqm.jpg?1 (http://imgur.com/IBuAtYq)

https://i.imgur.com/iMDX9lZm.jpg?1 (http://imgur.com/iMDX9lZ)

http://imgur.com/a/nZIA7

Tech specifications:

4 layers of copper, 2oz on each layer
4000w output with 2x DPS-2000 BB.
30x PCI-E connectors
On/off switch
Optional adjustable output voltage from 12v to 13.7v on the older DPS-2000 BB PSUs
Optional voltmeter if you want to adjust the output.

Sideplates with M3 threads (nutserts or similar) to attach both PSUs together and make the 120mm fans installation easier: 2 screws to remove from the PSUs, attach the plate, screw the fans, "et voila".

Expected price: $55.
Maximum size of first batch will be 150 boards.

Here are the pricelist and options:

Standard board without voltage adjustment:
1-25 boards total ordered -> 57$
26-50 boards total ordered -> 54$
51-100 boards total ordered -> 50$
over 100 boards total ordered -> 47$

Options:
Sideplate: $6
Adjustable voltage option: $5.5
Voltmeter with pin header matching the boards: $5.5

No volume discount available on options for now, my buy price is quite high.


Interest so far:

Username	Qty needed	Qty sideplates	Qty volt. adj.	Qty voltmeter	Paid in full	Shipped
dance191	10+	?	10+	?	yes	yes
klondike_bar	1-2	?	?	?	no	.
pinhead666	1	?	?	?	no	.
MarkAz	10-20	0	?	?	yes	yes
philipma1957	1	?	1	?	no	yes
Tupsu	4	?	?	?	yes	yes
fhh	2	2	2	2	yes	yes
fullzero	1	1	1	1	no	.
mindtrip	2-3	?	2-3	?	no	.
sloopy	1	1	1	1	no	.
jjiimm_64	?	?	?	?	no	.
jstew	?	?	?	?	no	.
Exoskeleton	10	?	?	?	yes	yes
--	00	00	00	00	no	.
shacky	10	10	00	00	no	.
smracer	20	00	00	00	yes	yes
--	00	00	00	00	no	.
--	00	00	00	00	no	.

First 50 sold. Shipping in progress.
Next batch in 10 days, 150 boards.

OMG! This looks great

nice!
are the right and left part corresponding to the psu's or how do i know i don't power same blade from 2psu's?

very interested. id likely take 1-2 of them.

dps2000 is nice because you can use any fans you like to control noise levels

We were working on an idea like that earlier this year too; never got to prototype but the idea is sound.

I'll take one.I like these dps-2000s too.

This board acts like a single 4000w PSU, no need to worry about which plug to connect here ot there

What happens if one of the power supplies dies, will the entire thing gracefully shut down?  Is the DPS-2000BB platinum rated also?

I'd be in for at least 10...

What would a full kit look like on price?   One with board, PSU's, all PCI-e cables, etc.

And congratz that is one heck of a PSU, nicely done.

same question as above!

does it work with other dpsxx00bb psu's?

do the load balance between them? or do you make some electronic modifications to the psu's
from what i know there is always a imbalance or something like that

yeah I have 2 s-7's on order.

I have 240 volt power.

I may want it.

boy if power went from 11 to 12.7   rather then 12 to 13.7 

as I suspect underclock may be better for some of us.

I am going to do various sound tests using. the items in the screen shots.  note the photos are lifted from ebay but I got some of it local for better prices.

the goal is 25db sound reduction

https://i.imgur.com/yE67gWK.jpg

http://imgur.com/yE67gWK,S8hLqSs,oCHMYvW#1

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

https://i.imgur.com/vQ5fo7r.png

 see if this works in the sonotube or the vent pipe right above

https://i.imgur.com/SESw4Gl.jpg

@Phil: why don't you try some ghetto ducting 2 or 3 12cm fans into 1?!?!?
my idea is move both fans that the s7 is coming with, on a duct at the front ;D

 Would make a TON more sense to be able to adjust the voltage BELOW 12v, but I suspect that's a PS-based limitation?

nice 4k bracket board  :o
but hard to find dps-2000 in my country.

And I'm still looking at a way to go under 12v because it can be interesting with the Ant S5 for example, but if it's even possible, it will very likely need extra components.


The second PSU will trip in overcurrent protection if the load is too high for it, you'll have to reset the board (off/on).


The PSUs are load balanced, like when they are in the chassis of the server.
And it should work with the DPS1600BB and DPS2500BB, but I'm not sure about the voltage adjust on those ones.
I have a few 2500BB to check.

Want One for sure!
complete kit with cables fan holder and voltage regulation.
Maybe a second one

Edit
find a solution to lower voltage would be fantastic

I'm working on an undervolt solution, should have prototypes this month.

I'm completely out of stock on DPS2K boards, but can get PSUs reasonable if he doesn't have a lot of stock. Pretty smexy setup, J4bberwork. The fan plate is an especially good idea.

Thanks for the comments.
If the PSU allows it, having a -0.2 to -1.2v sent to the A1 or A2 pins (12v sense) should allow 10.5-12v regulation.


To explain to people who are curious to know how it works, some PSUs are "sensing" the voltage drop as close to the delivery point as possible.
Usually, it's a voltage drop because of the length (resistance) of tracks/wires, and the amount of current drawn.
The PSU adjusts the output voltage to compensate and sense +12v at the delivery point.

Some PSUs circuits are made in a way that only voltage drop are compensated, since in normal operation the voltage can't rise across the wires/tracks.
Some other will still respond to a voltage rise, and will drop the output voltage accordingly.

What we are doing is tricking the PSU so it believes that the voltage at the delivery point is lower than expected. The response for the PSU is to send higher voltage to compensate.
There is still an overvoltage protection, usually around 14.0v, and also and undervoltage protection.
Some PSUs will allow down to +9v output, some others will stop just below +12v.

I tested a similar idea with an S5+ 1/3.  I took a Block Erupter Cube Case (already has 120mm fan attachments) and added acoustic foam in three levels with V cuts on each level.  Looked like

        
|VVVV|
|VVVV|
|VVVV|
|       |     

It was very effective at dampening the sound, and didnt effect temp more than 1C.  However, the foam is not designed to interact with that much heat.  The air becomes thick with offgassing from the foam ( its not worth potentially getting cancer IMO ).


J4bberwock I am interested in a breakout board.

What is the price you will be having on PCI-E connectors?  Will you carry those?

Also will you be selling the PSU's and what price?

I'm just trying to gauge price to get whole package set up.

this is clearly geared towards s7 so why add the 6pins connectors on the board?! just solder directly the wires.... also half crimping or whatever is called on the wires...
the monster will fit perfect between s7s on its side and ~5cm higher for good airflow

I've bought a fair amount of acoustic foam and this is the best place I've found for buying it.  I literally just bought some to do some additional soundproofing.  Typically they're cheaper than the eBay sellers, and are consistent in quality (I believe they actually do the manufacturing on some if not all of the types):

http://www.thefoamfactory.com/

 

First trials with the parts I had in hands, I was able to get the PSU down to 11.78v (12.25v is my stock voltage).
More tests when I'll get a few parts delivered.

If you're getting some good undervolting, then up my quantity from 10 to 20.  ;)

this is a good point - a version with a multiple terminals (possibly with their own secondary power switches) might be cheaper to build and the 1-ended wires (I sell these and also PCIe-PCIe in my sig *shamleess self promotion*) are about 10-15% cheaper

So do you feel there is enough interest to do your first run, and if so, when do you think you'd do it?  I'm in need of some more power, so just trying to plan if I should hold out or pick something up now...

There is enough interest for a batch.
I'll order everything to make the first 150 boards.
Estimated shipping time for the first boards will be 5th-9th of october.

I'll confirm price with options in a few days once I have the reply for the side plates manufacturing.

I love the idea for the side plates, but I am not sure if the shipping costs will be worth it.  J4bberwock, if you could price the boards with and without the side plates that would be great.

This project is exactly what is needed for the S7, I am excited!!!

Sideplates are critical to me - since these PSU's don't have fans in them, I can't imagine why you wouldn't want the side plates, and I doubt they would effect shipping in a substantial way.  Plus then you're going to end up having to hack some sort of fan option anyway, so why not have a nice clean option from the get go.

i would be interested in 2 or 3 of these once you have everything finalized let me know

Air shipping metal plates across the planet tends to be somewhat wasteful when a simple zip tie does the job.  But, I don't know the exact price for the plates with shipping, which is why I was simply asking for the 2 pricing options.  Once we know the price, we could make an informed decision.

If I zip tie the 2 fans or mount the fans to the plates it is about the same amount of work.  So, if it costs much more for the plates (with shipping), personally I would pass.  Like I said, I love the idea of them, but they might not be necessary if the added expense is high enough it can't be justified.

P.S.  Thanks for the foam link, that looks like a decent place.

I'll be testing undervolting the PSU below 11.8v this afternoon.

Regarding the sideplates, I believe almost everybody will take them, but they will be offered as options, as well as the small voltmeter. Once the voltage is set on one PSU, you  can use the same for the next PSU, so there is no real need to charge you one for each breakout board unless you like to see the LEDs.
There will be a header to easily plug/unplug the voltmeter.

J4bberwock, you are the man!  No matter what people are trying to do, you offer a perfect solution for them, thank you very much!!

Update on the voltage regulation:
I managed to go down to 11.58v, the extra cost will be around $4, I'm not sure it's worth it for the small gain we'll have in efficiency.
Below 11.58v doesn't seem possible via external adjustment.

On the S7, we'll power the chips with 0.64v instead of 0.67v, so efficiency would be close to 0.22W/GH instead of 0.25W/GH

Overvolting the S7, assuming you can provide sufficient cooling should offer the following results:
12.9v input, 0.30W/GH, 5,65TH (1700w at the wall)

Undervolting at 11.6v input should give something like this:
0.22W/GH, 3.7TH, (840W at the wall)

Obviously, Bitmain won't offer any support if we overvolt/undervolt the S7.

After a little bit of cheating (opening the PSU to adjust the voltage down to 11.8v), I'm now able to output 11.18v with external adjustment.

So, final design should be able to do from 11.2v to 13.0v to cover all the voltages supported by the BM1385 chips (0.60v to 0.71v) if you open the PSU and trim one potentiometer that is easy to access.
Without opening the PSU, the lowest voltage will be 0.6v below the original voltage of your PSU, and max voltage will be 1.2v over the original voltage.

I'll test load the PSU at both output voltages with some S5s during 1 or 2 days before I send a design for manufacturing the PCB.

Looks great! A few suggestions, if they don't make fabrication unreasonable:

First:
https://i.imgur.com/VVqWCnU.png?1 (https://i.imgur.com/VVqWCnU)
(From this presentation (http://www-03.ibm.com/procurement/proweb.nsf/7a84535a0acd580885256b3f000e250a/4611e3ca4d7ae83185256f19005a9f12) - slides 6 through 12 are the meat.)


Second:
The DPS-2000BBs cool better if they're spaced ~0.5cm apart and parallel - the ventilation holes
occupy a more favorable part of the fan disc and the flow between the units exposes a decent
area of hot metal and lowers the static pressure...



Really looking forward to this!

Id be willing to pay the extra bucks for the ability to control voltage this board will out last my S7 into future projects all of which id love the options to over or undervolt at my discretion if that can be an option id be all for it

Thanks for the tech data.
I'll have the sideplates laser cut or something similar, so using optimized holes won't be an issue.

Regarding the spacing, I'll anyway have 5mm to 6mm between the plate and the PSUs because of the standoffs and some clearance for the M3 threads used for mounting the fans.
It wasn't on purpose for a better cooling according to your second remark, but it's good to know that it will help.

Is there an easy way to display the amp draw instead of voltage?  The bling of LED's on them all isn't that compelling, but if I could see a live amp draw from each, that would be something I'd buy for each one...  Just slap a ACS712 on there and you're in business!  :)

Will it work with only 1x DPS-2000 BB ? (I only need 2000W)
I only have one S7 coming my way and I want to undervolt it.

Yes, but you'll need to connect it to one specific slot, and you'll lose the benefit of the side plate for easier cooling.

I just shared this on the S7 thread.  I hope you don't mind.  I think it's a great idea.  If you had rather I did not share it, I will take it down upon request.

Thanks, I hope I won't get too many orders because of you, there are only 24 hours a day where I live  ;D

Quick question - are you going to have a pin-header on it to turn it off/on?  With the PDU's I have, I don't think they can turn on/off two ports at the same time, there's a slight delay so it would be much better to be able to setup a relay to do that.

If you get a package coming to the US please put me on the list.
Nothing like flashing lights to excite me.

I want the deluxe model, all options possible, and definitely the fan shroud.

I have a stack of these supplies for backups. I need the board and the side plates.

I would be interested in this also....

subscribed!

What's the actual time table?

I need 10 of these J4bberwock! Let me know.

id also be in for some , these would make more sense then the ibm 2880's im using

Quick update, I was unavailable for the past 2 weeks, so everything have been delayed even if I have all the parts available except the actual PCB for a first batch of 120-150 boards.

The sideplates will be laser cut from 2.5mm acrylic panels like this (first test from 1.0mm foil before my brand new laser cutter died after 2 hours of use)

https://i.imgur.com/6dJ9hG3.jpg?2

I'll get a small test batch of 50 PCBs next week.
The first orders will be able to ship before the 6th.

In the meantime, I've started the assembly of the voltmeter to make it modular so you on't need one on each breakout baord if you don't want to.

I'll update the first post later with a few extra pics, price, and probably list of confirmed interest.
Will start to collect funds this weekend or beginning of next week.

BTC payments will go as usual to my 1J4bberW... address.

I'm in for 10 boards in the first batch, confirmed 100%. I got the BTC ready to go whenever you are. I would like boards with all the options as well as the side plates.

I count about 40 orders sharp so far and it looks like plenty of those orders are maybes. Even if every one of them is confirmed it looks to me like I can get my order of 10 in the first batch. I'm likely to buy 10+ more in the second batch, and if you have more than 10 available in this batch I'll buy up to 20. 

Thanks for the effort and awesome work!!!  ;D

Just so you know there are orders for them, I'll take as many as are available, up to all 50 (if no one else gets them).

Gotta love this. You'll take all 50... As if nobody else exists.

Ok. If he wants to let you take all 50 they're yours. You said you showed interest first. Wow.

I'm happy with 10 or even 5, everything else is nice.  If you want to get every single one and J4bberwock wants to let you then its all good. I think 10 max is fair. Even 10 each is only 5 people getting boards.

Lets let J4bber sort it out. If I don't get any boards this go around I'm not going to whine about it.

I'll arrange things according to the order of posts in the thread and private messages.
But don't worry, after I receive, solder, and validate the 50 piece test batch, I'll order a standard batch of 250 boards, 7 days delay, so everybody will have his boards.

Edit:

dance191 was aware of the project and showed interest in a lot of units before it was made public.
I was working on it when he asked for something with voltage regulation in August.
But still, for the test batch, I'll try to get everybody happy, and mass production will start by the 10th of november.

Price for a complete set please!

2*2k psu, breakout boards and cables!

Thx!

I am interested to buy:

1x Board with voltage adjustment
2x DPS-2000 BB
20x pci-e cables, all longer cables
2x power cables
2x side plates

Allready PMd to Jabber.

Voltage adjustment is really interesting feature. Then there woludn't be need for separate buck converter. I think there would be more undervolted machines in the future. 10-12V adjustemt would be enought for example S5 undervolting.

 

I was waiting on a lot of things for the accessories: acrylic sheets (arrived today), power cables (will be there tomorrow instead of today), and spools of wires for the PCI-E cables (arrived today instead of monday).

If you need voltage adjustment under and over 12v, the only option will be the batch I'll get monday and later batches.
The first prototypes didn't allow undervolt on the board, only overvolt.
I did some small add-on boards to test the undervolt.

First, change number of pci-e cables. I will take 26 pcs.

I would like to buy set with undervolt option. I can do some savings with electric bills. I can wait until monday.
Can you please send me invoice that I can pay my set?

PS. Is this your hobby or are you doing this for living?

It started as a hobby, doing boards for myself, and a few people here asked for a few boards.
Then, people were asking for so many boards that I had to register a company and do it as a full time job.

I'll prepare the invoice tomorrow.

Exo - You read my post wrong.  I was saying they are guaranteed to sell.  I was saying I will take whatever he has, I wasn't trying to *claim* all of them.  I was just telling J4bberwock not to worry about selling them, people will take whatever he can produce, and if they don't I will.

Just read what I said again, but with above in mind, hopefully it makes more sense now...

Hi J4bber,

Please add to list. I want 10 boards with sideplates,

Thanks

Please add all options to mine;

Sideplate: $6
Adjustable voltage option: $5.5
Voltmeter with pin header matching the boards: $5.5

Thanks

Man I feel like a d1ck now... I was in a bad mood when I posted my little rant. I'm feeling better now and I hope there are no hard feelings. J4bberwock is doing some great work and I don't want to distract from that. If I can get a few boards still that would be nice. Otherwise I will wait for the one week delay. Its all good  :)

Just sent payment to your address. 10 boards, 10 side plates, 10 adjustable voltage options, and 10 voltmeters. Thanks man.  :)

I'll take more in the next batch.

If Its O.K. , and they are available to me, I'll take more in this batch. I have 60 of these power supplies so I'm in for 30 of everything total.

Just sent the BTC for 10 boards - I'll let everyone else get whatever they're after, and I'll pick up another 10 once the dust settles.  I don't want to hog them all!  ;)

I'll send the first boards today to Tupsu who paid 10 days ago.
I need to change the connectors for the voltmeter, so the ones sent this week won't work with later boards sent next week.
The sideplates have been slighty modified to use another locking spacer that works better with 2mm thickness of the plate.

I'll take new pics according to those changes and post a quick "how to setup the boards".

pm'ed

I've been away, just sent you the tracking number.

paid my order on the 5th.

when will it be processed?

got a tracking ID
THX J4bber!

Paid in full for 10 boards with all the extras on the 4th. I too was hoping to get a tracking # soon.

I want to order from the next batch of 5 pieces.
Today I got my ordered 4 boards. Thank you.

https://i.imgur.com/nM7Vqmu.jpg (https://i.imgur.com/nM7Vqmu.jpg)
Click to enlarge

I want to order one board from the next batch.

Is shipping to US included, or is it extra? I would like to buy 2 boards but wanted to be sure about shipping.

received my order:)

its great.

everyone be sure to use 2 DPS2000 from the same series.
I first havent looked after it and then only one PSU was working.
2 S7 were to much for it so it shut down after a few minutes.

nothing bad happened :) 

for the next order I would consider to order two sideplates per DPS-double because the plastic plate is not so solid.

@J4bber
at the Hi/Lo voltage switch I'm missing the "normal" middle position.
it is very hard to get it to the position of normal 12.2V
Lo is 11.8
Hi is 12.6

switch seems to have only two positions like the on/off switch
not three like the on/off switch from the single DPS-2000 breakout board

little space for improvements but you definitively get a wonderful 4K watt PSU monster :) :)

shipping is on top and not so cheap to US
maybe they will get available at the US distributor ?
mentioned here https://bitcointalk.org/index.php?topic=738527.0

actually it is not listed and the single version is also sold out:
http://holybitcoin.com/product/dps-2000bb-breakout-adapter-board/

Thanks for the feedback.
regarding the  different series, do you mean revisions? I've used mixed revisions with success, but they were both over S9 or under S9, I haven't tried mixed old/new revisions.

As for the voltage, adjusting the trim pot fully on the left side will give the lowest offset voltage.
After you adjust the internal pot for the lowest voltage of 11.2v, you should find 12v easier to reach.
I'll anyway change the switch with a ON-OFF-ON one for the second batch, no extra cost, and it can be of some use if you just want to use 12v.

All remaining paid orders should ship tomorrow, I'll provide tracking number.

Once everything is finally shipped I'll post some more detailed instructions for assembly.

Basically, you need to start by adding the breakout board to the 2 PSUs.

Then, the plastic locking spacers in the 4mm holes at the back of each PSU.

Unscrew the small screw close to the front of the PSU, and put the metal spacer in its place.

You can now put the sideplate in place by gently pressing the 4.8mm side of the plastic locking spacers in the sideplate holes.
And add the two M3 screws to attach the plate to the metal spacers.

In each set, I supply the M3x30mm screws to attach 25mm fans with grills to the sideplate.

If for any reason you do prefer M4 threading on the sideplate, just message me so I can adjust it before shipping.

Finksy will manufacture them for North America market starting in a few weeks. Same as he is already doing for the bladecenter 2880w boards.
Shipping from me for 2 boards to the US will be something like $35.

Holybitcoin will receive a batch of more standard boards including some single DPS-2000BB by the end of this week.

Yes I meant the revisions
Mixed 7 with 8s -> only the rev 7 had power draw: 2.5KW
The 8s was ideling @ 30 watt measured with Fritz! DECT200

2x 8s working perfect

hey what is power swing volt wise?

the avalon 6's could be a better fit with this the the s-7's   or are you only 12 volts and higher?

I've been quite busy at home for the past week, will update infos and pics soon.

Those particular PSUs are limited to 11.2v on the undervolt side, 13.5v on the overvolt side.
Revision S9 or lower will only need to adjust an internal trim pot before it's able to reach down 11.2v and go up 13.0v.
Without this adjustment, you'll only reach 11.6v and will be able to go up to 13.5v

Revisions S10 and higher will need one missing connection to be added on one board in the PSU.

https://i.imgur.com/Pup7jwEs.jpg?1

https://i.imgur.com/0MoaZA8s.jpg?1

https://i.imgur.com/yUWW4kPs.jpg?1

https://i.imgur.com/r9bXL92s.jpg?1

hey j4b,

2 of my 2000bb has only AC lights, no DC. before it was ok then now no more DC green LED light upfront. the breakout boards are working fine on other 2000bb's.

i can also hear a relay clicking sound.

any tips will be appreciated.

i need 1 2880W breakout board sent to me.

sorry not really related though but you are the guru of 2000bb + 2880W psu's & the breakout boards master !

pls do pm me when you are free.

are these correct psu's


http://www.ebay.com/itm/252144440397?

yes
good price <- edit: seems to be normal for US

Is your breakout board able to handle 5000w if DPS-2500BB are used instead of DPS-2000BB?

If you want to easily have the voltage adjust working, ask them if they can ship you revision number lower than S9M.

If they can't, you could use some zero ohm resistors to mod according to my pictures a few posts ago. I used pins salvaged from dead DPS2000 PSUs on mine.
Those resistors should do the job if the leg diameter isn't too big (looks ok on the picture, and some people used actual cut legs from resistors soldered together to replace the pins):
Ebay item 201428019892
Ebay item 121097959648

Just to be safe, I'd put them in some heat shrink tube in case the actual resistor body could touch another pin.

If you don't have an hot air station and a solder sucker, you can even carefully drill with a 0.7-0.8mm drill bit in the center of the solder pad that is missing the pin.

Total length of the pins is 42mm. I haven't been able to source them from regular sources like digikey/mouser...
Will try from my main connectors supplier.

The board have more than enough copper thickness and layers to handle 5kw.
But it seems external voltage adjust doesn't work on the 2500BB. I still need to try on the ones I have.

they read s7.

  I have your 2x board on hand  I will post assembly > when all pieces come on hand.

J4bberwock,

Its been a while since I've read this forum.  What I'm about to ask may have already been asked:

Do you have anything in the works for something similar but with IBM 2880W PSU's?  It might be worth coming up with something to control the voltage on the 2880 and have a digital meter for it's output voltage.

I have a little over 20 x IBM 2880's at my disposal with your breakout boards.  I may invest in your setup for this present design in the future [Once all of my 2880's are in use].

Hi, I've probed the 2880w PSU for voltage control pins, and it's not easy to move it from 12v. I still need to try one easy trick just in case it'd work.

The only practical way someone found until now is to use an arduino to reprogram on the fly the internal ROM of the PSU to allow different voltage outputs.

http://www.rcgroups.com/forums/showpost.php?p=30428005&postcount=2972

The same thing can probably be done to output lower voltages, but it's a bit overkill just to allow us to go from 11v to 13v

Okay,

Thanks for the reply, Sir.

EDIT:  After reading the link, I must agree...  It's overkill.

Hey Dwardjr i have a few of J4bberworks break out boards best thng going right now i like how we can plug into PCEI plug to plug . :) . just bought one of his 2000 blade center boards, not this one, they are very nice. .

Agreed.

J4bberwocks HW is the shiznit!

Is there anyone powering 3 S7 with this? Which fan do you use / recommend for cooling the PSUs?

I am. (https://bitcointalk.org/index.php?topic=7216.msg13186101#msg13186101) My own contraption, but the same end result as j4bber's breakout board. His solution is just much more elegant. I'm using 2 Delta fans, approximately 150CFM each. Could get by with lesser fans, but I had these on hand so why not.

Sometimes, PDU's come into play.  For instance, my 30 amp PDU's have two 15 amp legs.  15 amps x 220 volts = 3,300 watts.  6,600 watts maximum with both 15 amp legs combined.

I'm presently using IBM 2880 PSU's to power 2 x S7's on each PSU.  1220 watts x 2 = 2440 watts.  I might use 2 x IBM 2880's and 1 x Corsair AX 860 on one 30 amp PDU to power 5 x S7's instead of using only 1 x IBM 2880 alone on each 15 amp leg of the 30 amp PDU.  However, more than likely, I will end up powering only 4 x S7's with 2 x IBM 2880's for each 30 amp PDU to remain well within the 75% allowed for each circuit.

I may probably go with this new setup J4bberwock has come up with once all of my IBM's are in use [22 x total IBM 2880's].  I would have the option to power 5 x S7's comfortably on one 30 amp PDU with 2 of these new setups of J4bberwock's [One for each 15 amp leg on the 30 amp switched PDU's].

Man, I can't even imagine the noise 22 of those would make.

Why are you only getting 220V from your service? Should be 240V. Mention that when the engineer comes by, he'll send a team of linesmen to increase voltage on the transformer in the pole. They bumped mine up after I complained about having only 227V with my heavy load.

It really depends on the meter you are using.  Most of the meters I use have an internal resistance of 10 million ohms or higher, which gives a 240 Volt reading.  If you use an old analog triplet model 310 meter with an internal resistance of 1 million ohms, you will see approximately 220 volts.  The less resistance the meter has internally when measuring voltage, the less voltage you will read.  The higher resistance internally inside the meter when measuring voltage, the higher voltage you will read.

Also, I'm reading 11 amps on a PDU that powers two S7's [Batch 1] with an IBM 2880W PSU.  If you multiply 220 Volts x 11 amps, you get 2,420 watts.  If you divide 2,420 watts by 2 S7's [Batch 1 @ 600 MHz), you get 1,210 watts.  How many watts were the S7 batch 1 clocked at 600 MHz rated?  Answer:  1,210 watts.

The internal resistance of ANY meter [When measuring voltage] is high.  However, some meters have higher resistance than others.  Some meters [Especially analog meters] have "ranges" you can select when measuring voltage and the internal resistance of the meter can vary depending on the range you have chosen.  The Triplet model 310 states on the meter it is 20,000 ohms per volt internal resistance.  If you put the meter in the 60 volt range, 60 x 20,000 = 1,200,000 ohms internal resistance.  

If you were in the 120 volt range, the internal resistance would be 120 x 20,000 = 2,400,000 ohms internal resistance.  If you were in the 300 volt range, the internal resistance of the meter would be 300 x 20,000 = 6,000,000 ohms.  Which see:

https://i.imgur.com/Xb28GqC.jpg


The previous internal resistance when measure voltage concerned measuring DC Volts with a Triplet model 310 analog meter.  When measuring AC Volts with the model 310, it's internal resistance is 15,000 ohms per volt.  Which see:

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


If you were in the 300 volt range with a Triplet model 310 measuring what you may think is a 240 volt circuit, you would see approximately 230 to 233 volts because it has 4,500,000 ohms internal resistance in the 300 volt range (300 x 15,000 ohms per volt AC).  If you used a Fluke digital meter with an internal resistance of approximately 8,000,000 ohms to measure voltage on a 240 volt AC circuit, you would see approximately 240 volts.  The internal resistance of a meter when measuring AC Volts is generally a little bit lower than the internal resistance of the same meter when measuring DC Volts.  However, they are both (AC and DC) still quite high.

I do not doubt you read too low of voltage at 227 volts with your meter.  The power company can adjust the voltage output on most transformers.  All I'm saying is the amount of voltage one reads can vary by what meter they use.  Especially, if they switch from an analog to digital meter or vice versa.  

If you look back at my previous statement about the 11 amps reading on my PDU, that will tell you my voltage in my home is 220 volts when you compare it to how many watts 2 x batch 1 S7's will consume when set at default of 600 MHz [1,210 watts each for a total of 2,420 watts].  I've seen a lot of 3 Phase voltages read 208 volts.  Does this mean the voltage is too low?  No, that 208 volts would be read with an analog meter with a lower internal resistance than a digital meter set to a higher internal resistance that reads about 215 volts.

Many people who work with electronics on an everyday basis will tell you they are careful about what meter they use when measuring voltage on a low voltage circuit verses a high voltage circuit.  It can make a big difference.  Especially, with low voltages.

I think you know I'm getting a power upgrade here at my house soon from 200 amps to 600 amps [or at least 500 amps].  I'm going to ask the engineer [When he arrives in the next few days] what the line voltage is on each phase coming into the neighborhood.  It's very possible the line voltage is 240 volts or 480 volts and the transformer is stepping it down to 220 volts instead of 240 volts.  If they in fact have 240 or 480 to start with before knocking it down to 220, I'm going to ask for a transformer  that knocks it down to 240 instead of 220.  It may be they have a transformer they can install to adjust the voltage output to 240 for me.  Many transformers have that capability depending on where they terminate the feeder cable on the coils in the transformer.

Again, the reason I believe my voltage is actually 220 volts is because of the amp reading I'm getting on my PDU with 2 x S7's that are batch 1 and set at 600 MHz.  They are supposed to burn 1,210 watts each at the wall.  Two of them would be 2,420 watts at the wall.  If we divide 2,420 watts by the 11 amps I'm reading on the PDU, it equals 220 Volts.  I'm definitely asking them if they will increase it to 240 volts when they install a new transformer.

Thanks for the detailed and educational post on the meters, I had no idea. I used the same meter, though, to read the change from 227v to 240v. Also, my 227v reading went back up to 240v if I removed the load. The sag was caused by the power load and heat from summer. Winter temps are definitely helping right now.

No utility sets a transformer for 220v, they're all set to 240v. If by voltage coming into the neighbourhood you mean the top most wire bare (or 3 wires if 3 phase is available in your area) it's neither 240v nor 480v. In fact, quite far from it. Those lines run at 12200v or 14400v generally, and are transformed to 240v before they enter your property. When you read 208v on 3 phase, that's quite normal. 3 phase systems in the low volt range are 120v/208v, not 220v or 240v.

Oh, don't forget that your 1210w figure depends on a PSU with 93% efficiency. 2880w are no where near 93% efficient according to the tests I did. (measured DC output vs AC input) Not a good way to calculate your voltage.

I went ahead and ordered mine from finsky here in the US  ;D

How much was the total?

works with 2500bb with adjustable voltage ? i'd assume it should

Thanks for the reply.  Sounds interesting.  I'm wondering if the 220 I'm suspecting is after voltage drop across the 2880W PSU with a load on it when I do the math?

What did your psu show  90% or less?

I just checked it, and it doesn't. And I can't see anything that we can connect to make it work at first sight.
The internals are different between the 2000BB and the 2500BB. I'll have a look at a 1600BB if I still have one in stock, but it should be the same as 2000BB.

J4bberwock,

Can you get me PCI-e cords ASAP?

Just curious if you can.  I haven't ordered any from you yet... But I want to ASAP

EDIT:  YOU ROCK, MAN!!!!

THANKS!!!!!!

ah ha ! lucky i asked. but the pinput diagram "looks" the same between the 3 models.

will wait for you to check & see how it goes.

thx for checking it ;)