Topic: Antminer S5 - Underclock - Undervolt - Best J/GH - page 15. (Read 31090 times)

Phil do remember that the S5 is yet to be understood & the S5+ is completely uncharted. You would be hoping that the S5 solution is something like the multiple Clock Modules and that they carried that design through to the S5+

Rich

your research on this is to be commended.  I really think it would allow some s-5's

v1.9, v1.91  an under clock

I also think it works for the s-5++   if so  the s-5++ becomes a better piece of gear.  For the home miner.

I ordered btc from coinbase it arrives this friday. I will order the s-5++  and test it.

If anyone wants to run a test on their S5. Remember you do not need a high current supply to do it. Only connect one of the hash boards to the supply, the one with the 4 pin connector to the control board, this will halve the current needed for the test.

Set the frequency to 125Mhz. You then just need a supply with a voltage between 9.25 & 10 Volts at 6 Amps and that will be good enough to give a strong indication that the tested S5 will or will not support undervolting.

For a quick test you can probably get away with putting two or three 10 Amp Silicon Diodes in series with your 12V supply. You will need to monitor the voltage getting to the hash board when it is hashing to find the exact voltage it is running at.


Rich


Just to add. The most important board to test at this stage is a V1.9. As far as I can see it's identical to V1.91 but without the additional Clock Modules. If this does not Undervolt almost certainly none of the earlier versions will.

 so the facts are the early versions tested don't do well at 9 or 10 volts


the newest version did great at 10 volts  even 9.5 volts.

v1.1   2014-12-03
v1.3   2014-12-15
v1.5   2014-12-20
v1.7   2014-12-22
v1.9   2015-01-08



one from below was able to clock low

v1.91 2015-03-28
v1.91 2015-03-28 -With mini heatsinks

so we need the people that tested and got bad results to get back to this thread and let us know what boards they tested.


Like you said it may be multiple units of s-5 can do this.

not just version v1.91

this would let the 'good s-5' run at 650gh 200 watts and with quiet fans.

it may allow  for the s5+ to drop to 6th and use only 2400 watts.

lots of possibilities.

I think I may get an s-5+ and test this out. rather then get an s-5.

P.S. don't be sensitive to my style of writing I have been through a lot on this site and have been pretty blunt.

  I  would think this thread should get interest and it does not get a lot.

 I am making an effort to acquire  some btc and get  the s-5+
I would like to think it can be down clocked to a sane sound /power use via your methods.

I have collected together a set of pictures of all the S5 hash board revisions I can find, may or not be complete, but it's enough to be getting on with. Here are the pictures along with my initial comments on the changes. There will at this stage almost certainly be errors & omissions, this has all been done in a quite short period of time.

V1.1   2014-12-03




First release. Easily identified by the large cleared copper areas.

VDD decoupling components on the front of the board

Only 5 of the 6 possible level shifters placed

16 Pin connector to controller board

PCI-e 6 pin power connectors close together in S3 compatible position

Single oscillator module Y1 on the ground level chip.

Credit to dogie for a decent high res pictures, wish the others were as good.


V1.3   2014-12-15




Move to 18 pin connector to controller board. (Have not investigated what the additional signals are for?)

PCI-e 6 pin Power connector spacing widened, not S3 case compatible any more.

All 6 level shifters fitted along with additional SMT chip marked G07F. I think this is a SN74LVCG07 Buffer / Driver chip. Possibly / probably associated with the additional data connections from the Controller board?

Single oscillator module Y1 on the ground level chip.



V1.5   2014-12-20



No immediately obvious difference to V1.3 but have not examined that closely.



V1.7   2014-12-22



VDD decoupling components moved to reverse of the board. I have assumed they have been moved to the reverse as I do not have a picture of that side of the board.

The cleared copper area on the reverse of the chips is now a clear rectangle. I could guess clearing the way to easily fit a mini heatsink that comes later.



V1.9   2015-01-08



Board layout changed to make provision for additional oscillator modules. Y1 to Y5. See V1.91 for more info.

Also provision for Oscillator modules on all stages Y1 to Y16.




V1.91   2015-03-28



Additional oscillator modules Y1 to Y5 fitted. The level shifting chain is broken at each of the points that an additional oscillators are fitted. Each oscillator drives 4 pairs of chips, and the last on in the chain 3 pairs.

Addition. The LDO regulators on all but the last stage are removed. Voltage for the IO & PLL is now taken directly from the Core Voltage of the stage above.
This is a significant change & means that the IO & PLL voltage will track up and down in proportion to the supply voltage. Also it might have been possible (Have not measured) in the earlier boards at lower supply voltages for the LDO, which took it's supply from the core voltage 3 stages up, to drop out of regulation.


V1.91 2015-03-28 (With Mini Heatsinks)




Another version of V1.91 built with mini heatsinks fitted. Look the same as the ones fitted to S5+, so perhaps a trial? Do not know why they, on all the ones I have seen, did not fit heatsink to U20 & U29?



So there are 2 "big" changes that have taken place. First was on the transition from V1.1 to V1.3.The 6th level shifter was brought into play along with it's Driver Chip. The change from 16 to 18 connections to the Controller Board and the other Controller board changes was also made at this time and may be associated with this?

This could be the key change, but have no way, at the moment, of confirming that. I suspect it is not, but it would still be useful to understand exactly what this change does?

The second change is the one I am putting my money on being the key enabler of lower voltage working. V1.9 of the PCB made provision for additional oscillators, at V1.91 they were fitted.

The Oscillator count goes from 1 to 5 and the oscillator level shifting chain is broken at each of the points that an additional oscillators are fitted. Each oscillator then drives 4 pairs of chips, and the last on in the chain 3 pairs.

This change is consistent with one of sidehack's theory's that some of the signals are not making their way through the chain if the voltage is too low.

There are also pads on the layout for an oscillator for every pair of chips Y1 to Y16. These additional Oscillators have a different pad layout to the fitted ones Y1 to Y5

My S5 is has the V1.91 with heatsinks and can definitely be undervolted as shown in my previous posts. Most of the testing was with the 20150415 Firmware, but over the last few days have been using  20150715 with no noticeable difference.

I want also to take a look at the LDO regulator(s) for the PLL Analog & Digital power. Silly thing is I can only find one. It's either staring me in the face, on the reverse of the board or not there? I am sure that sidehack could put me right here.

If this all works my favoured solution for powering would be a modified Server PSU. They mostly have provision for a small adjustment 11.7V - 12.7V. I think some can be adjusted more than this, perhaps you could jack the sense input up and reduce the voltage? If anyone already has a solution, or wants to take a look that would be great? I am not that keen on the additional complexity, cost & reduction in efficiency of an additional VRM.

More to come but I have now shared everything I know and if anyone else wants to pitch in trying versions or understanding the changes please do so and let us know what you find?

Rich

I'd prefer something that would go AC line -> 9-10V range with 90%+ efficiency, not ignoring your bucks but they are extra bucks.
I'm also not convinced they're good for 15A in a mining setup.


 A couple of the other converters they list mention higher power output with a heatsink upgrade, though. Would have to look into the details.


 Might be worth looking at next summer after the halfing as a way to keep my S5s hashing at a profit for a while longer (don't need them on my SP20E of course), but I'd prefer to figure out how to adjust the voltage down on my existing power supplies.

I am slightly annoyed with these comments, but I guess I am new so have to put up with it...


And that...


I did not stumble on it. I read the data sheets, looked at what sidehack has done and decided to find a way of making an S5 perform at a lower voltage. 

All I have tried to do in this thread is to share the information that I had found, albeit in an incomplete state, not to be taken to task over it's validity.

MarkAz thanks for your support, now let's move on.... 

I was wishing in some ways that I had just kept this to myself until I had done all the work to understand what the problem was and how to fix it, but thinking on it overnight this project is going to go ahead much quicker with some help.

My best theory at the moment is a simple one, that S5 working at a lower voltage is Hash Board specific, with changes being made in later versions which then make it possible. I am assuming that tests done by others were on earlier versions of the Hash board? They did not add the version to their posts, so I cannot prove that.

I can't afford to go out and buy a version of each of the revisions of the S5 in order to test and prove which versions work at a lower voltage and which do not. So I am collecting all the paper research I have done and my guess at what the problem / key change was, and will share as soon as I have put it all together.

Rich

the buck step down I linked is 95% and can handle 15ampa at 10 volts.  so 2 for each s-5 is about 30 dollars

doing better then 95% is not going to be easy.  and 95 percent of a 93 percent platinum psu is a 88 percent psu.

my method will work but costs too much its would be 30 bucks an s-5 and add a few more for cables .  so close to 40 an s-5

 Why not split them out a bit, should be able to run 5 easily split between 2 circuits. 2 one one circuit, 2 on the other, 1 split between the 2, without pushing a 15A 117VAC circuit particularly close to it's limits.

 78xx and LM317T are both fairly low current limit - 1 AMP for the 78xx series, I think 5 Amps but might be a lot less for the LM317, can't remember for sure since I've not worked with those in a while.

 Both are also VERY inefficient.

 It's possible to use an external pass transistor with them to up the current limit, but you're still dealing with a LINEAR regulator, and therefore VERY INEFFICIENT.


 Finally found my guestimates - in the RBox upgrade thread, not the thread I thought I posted them in.

 S5+ turned out to be a bit more efficient than my 16-per-string guess, but looking back at that guess I think I misfigured a bit - it should have been better efficiency that a stock S5.


 The figures posted for .6 are higher on GH per chip, but not by a lot, and pretty close to dead on for power-per-chip between my guestimate and the "9v" figure posted.
 I don't see ANY reason to doubt the posted "as measured on a S5" numbers, they're right in the ballpark of where they SHOULD be based on the published specs for both the S5 itself AND the BM1384.



 The real trick now is to either figure out how to turn the +12V on a low-cost EFFICIENT power supply down to 9-10V range, or find a higer amperage capability converter that can do 12V to 9-10V range, or find a high amperage PS that is high efficiency in the 9-10V output range.

Awesome!! 
I needed this, was thinking of a way to put 3 S5's on 1 breaker... just happens I'll need to lower 1 out of 3 to make it happening.
This kind of detailed listing, in this type of business should be given by Bitmain themselves... but some people have equipment, so amen.
Now I can buy more miners and increase my hashing power.... price of Bitcoin right now, the only thing worth spending on in hardware.
With this I'll be able to add an extra 3TH.s for sure, if not 4!!
Now with the S5+ that will push back the release of any new processes, not a bad idea to further invest in used S5's...

Might not be 100% accurate but it's a good rule of thumb to start with.

Just a comment on these points. The HW errors are sort of deliberate. The S5 seem to very smoothly go from no errors to a few to a lot as you wind the volts down at any given frequency. So for each of the tests I adjusted it to be just into errors as this was an easy way of knowing I was on the edge. In practice you might want to add 0.1V to each of the levels, and they may well be differences between machines and on mine there is definitely a difference between boards of a bout 0.2V.

I think the BB/Controller is absolutely fine at 10V as it's ok at 9V, but definitely on the list of things to check.

I left the fan connected as normal as this seemed a fairer test, and if it was oscillating between 2 speeds took the current at the higher one. At this stage to be honest I was not after the last decimal point of accuracy, this was about does it work....

Rich

I'm totally with you - I would love to run a bunch of my S5's at greater efficiency vs greater speed.   It also means that you'd have a longer lifespan for the device, as difficulty raises you can slow it down and boost up efficiency.  I'm not a huge fan of the step-downs you found, but for testing things out they'd be fine... I think the ultimate solution would be to pick some decent power supply, and reverse engineer it enough the change the 12V output to some alternative fixed amount.

But the big question is probably less about whether or not the device can run for some period of time at a lower voltage - but how stably it does.  In the screenshot you can see he's got some hardware errors - and maybe his S5 has a bunch running normally, but to me that's reminiscent of overclocking - ie; the closer to the edge you get, the more errors you encounter.

The only other thing to consider also would be whether or not to pull the BB/Controller off of this voltage adjusted input - I can't think there's a reason you couldn't run them at 12V and just undervolt the blades.  The BB has a voltage regulator already in it, so it should be pretty tolerant in either case.

Ah, one other thought - are you running the fan off of this?  I notice the RPM is 2040, so one thing that could skew your numbers would be variations in what the fan pulls.  Personally when I do power calcs, I usually put the fans on a separate PSU just so I can focus on the device, and then run the fans at full so I know the worse case fan draw.

I am going to  rescind my offer to ship those converters out.  I am going to order my own s-5 and try to duplicate the op's results.

@ op  what was your firmware and board codes?

philipma1957, while it's cool you're making the offer, personally I don't think it matters at this point... He's still in the process of testing things out, and has been posting more updates than soliciting anything from anyone.  I don't think there's some immediate rush that would necessitate running out and verifying his results quite yet - and once he's nailed down things, I'll be more than happy to buy the converters myself and test on one of my rigs.  I'd rather see you buy them for him at that point, so the person spending the time figuring things out doesn't have to eat all the costs, instead of just some random guy who verifies his result.

I also think RichBC is spot on with his comment about the obsession primarily being hash rate, and while people get excited about efficiency, when you tell them their 1.1TH would be running doing 400GH, their interest wains.  

And to RichBC, love the work - and welcome to the community, but I think to philipma1957's point, this space is unfortunately filled with scammers and most people have gotten their hopes and dreams smashed against the rocks of reality on more than one occasion on here.  The nice thing is that once you're a known quantity, the community is very supportive and active - look at Sidehack or some of the other hardware threads out there and you'll see what I mean.

Either way, keep up the good work!

Thank you


  my reasoning is this .  You may have stumbled on an improvement in :

A) firmware
B) pcb boards

I pushed hard because I wanted you to be correct.

Now that I see photo proof.  I don't mind buying gear to test out your findings.


I am like you in that my power is costly  so for now running s-5's  that do .51 watts a gh does not work well for me.

But if you have discover something that can be duplicated on other s-5's

Even if only a certain pcb with a certain firmware.  You have found a great secret and shared it to the rest of us. For that you did very well by all of us.

Would not it be nice if 20 to 30 percent of s-5's can clock as you claim?



your gui and meters are showing about 180 watts dc  to  get 578 gh   this is   180/578 = 0.311 watts a gh.

I would set up an s-5  right away based on this.

Phil I think you are being a little unfair, I am not asking you to trust me or to go and buy anything, and even if you were to experiment why not just buy one converter?  You are trying to push this along too quickly. So while I work on the proof, a couple of points to ponder on.

1) The data in the BM1380 and BM1382 data sheets, Core Voltage & GH/s and J/GH has been shown to be correct so why doubt what is possible with the BM1384?

2) sidehack has shown similar efficiency is possible.

3) This is not actually that relevant to most people at the moment. It is to me because of my electricity cost 0.943 Pence / KWH (14.7 Cents) This is the pivot point for an S5. At current difficulty and 15 Cents you are best profit wise to run an S5 flat out. If your electricity cost is lower than this then Overclock. If your electricity cost is higher then Underclock.

4) I had expected this to be a long haul and had prepared the following post as an introduction to the project. I then expected to have a string of posts over a period of time explaining my progress, successes and failures.

This was then going to followed with.


However I posted none of this because I switched on the S5 turned the volts down, made some measurements and posted them.


I am now working on why it works however this is hampered by a few things.

1) Most of my effort, in the time I have for mining, has gone it to making a set of measurements to validate what can be achieved

2) I only have a single example of an S5.

3) Working with the string design is not very nice. You do not have a nice common ground and the ability to easily make measurements and to hook the Logic Analyser up to multiple points. You have to be very careful what you are earthed to at any point in time otherwise there will be a big bang....

Finally for what they are worth a couple of pictures.



Here is cgminer showing the run at 175MHz



And here is a shot of the PSU on the same run. 10.0V on the PSU but then 9.8V on the meter measured on the board and 17.8 Amps being taken.

Best I can offer at the moment....


BTW testing with those converters has no value at the moment. They will almost certainly be fine with my S5. The key issue is understanding why this works which is what I am going to work on next.

Rich

So here is a screen shot of the two convertors each can go down to 10 volts at 15 amps and supply 150 watts.

so the s-5 will be able to get 300 watts  which can run freq 200   using 206 watts and hashing at 665 according to your graph.

Well look at it from my viewpoint.  My power cost is high.


 I can get those .95% efficient buck transformers I linked to you.  they would take my 93% plat and drop it to 88% which is solid gold rating.

If I get 200 watts and 610 gh   for an s-5 it is great.

I could run 2 s-5's at 1210gh  use 400 watts.

I now need to decide do I want to trust you and spend  4 x 15 = 60 dollars for the dc to dc  and 700 for 2 s-5's.

 I am 760 out of pocket if you are wrong.

Now it could be some units do what you claim So I have to hope I get the right version.

So lets say I do.

  the upside is  really quiet s-5's running at .33 or .35 watts a gh.

I have lots of  power supplies. I do not need to buy one.

I just don't feel like doing all this testing  based on your word alone.

No screen shots of a gui really look bad on your part.

Now I have those buck converters listed. 


 Here is what I will do anyone with good long rep here  I will buy 2 converters and drop ship them to you so you can test your s-5 and see if you can get  these good numbers.

2 convertors would give you 150 watts each so your s-5 can run at 10volts at freq 200 and do around 600gh  which would be 200/600 = .333 watts a gh

Gotta say if there is one thing about my limited time mining I don't like, it's the lack of trust that there is in this community.... If I wanted to scam people I can just as easy edit some screen shots, but why would I, what's in it for me? I will try and do what you ask for but if you think about it there is nothing that I can post up that will actually prove what I am saying...

Here for what it's worth... is the complete table of measurements I have made.


A couple of notes on the table.
1)They are measured in amps & volts output from the adjustable PSU, so are not At the Wall, you need to add 5-10% dependant on your PSU efficiency.
2) One of my hash boards is prone to dropping out below 9.25 volts so the data at 100Mz is not sustainable, the best efficiency is in practice at 125MHz,

I agree BTW with your comment on lack of interest. I put it down to my newness and most peoples obsession with overclocking....

Rich