[GUIDE] Undervolt antminer s1 [1.19W/GH at the wall]

[davecoin]

Just wanted to say thanks to OP and others here.  I have 3 ants running at 541 watts on a DELL 750 watt server PSU.  All are running ~140Gh/s with <0.5% errors.  I used the pencil method and a cheap multimeter.

-Dave

[tzortz]

So, whats your total hashing now?

[WinterParker]

nice job!

however, I dont see any point to unervolting at this point. maybe by late summer when the the difficulty is as high as the temperatures, but right now getting the most hashes per second is my focus

If you have no more space, no more power and the room is getting too hot, this is helpful. 

check, check, & check..... undervolting it is!  so I can stop blowing breakers over here..

[Brassguy]

@Trends The 10k pots work great!

Chips are at .91v
Frequency 300mhz
Hashrate 153gh (<.5%  HW)
Wattage 216w at the wall

[Trends]

If you have the skills it's the best way to go.
Congrat's. Got pic's?

[marunga]

Hi,

I suggest multi turn pots. Glue them with double-sided tape near the orange caps and use pcb jumper wire to connect to the resistors (the type of wire used to repair PCB tracks).

The potentiometer in the picture is not soldered to the resistor, but you get the idea...

http://31.media.tumblr.com/ca128cd98d3d84d9ff29d52efc6fc045/tumblr_n6yhjviglj1sepsqdo1_1280.jpg


rgds,
m

[Brassguy]

If you have the skills it's the best way to go.
Congrat's. Got pic's?

Sure do! sorry for the bad pic, I put it into service immediately

Hot melt glue, 10K pots, works great!

[wpgdeez]

If you have the skills it's the best way to go.
Congrat's. Got pic's?

Sure do! sorry for the bad pic, I put it into service immediately

Hot melt glue, 10K pots, works great!

So you used a glue gun instead of solder? How much do the pots cost?

[Brassguy]

If you have the skills it's the best way to go.
Congrat's. Got pic's?

Sure do! sorry for the bad pic, I put it into service immediately

Hot melt glue, 10K pots, works great!

So you used a glue gun instead of solder? How much do the pots cost?

No. The hotmelt glue was for the pots and wires... standard solder used for the wire connections. Pots were 50 for $17.20 shipped via ebay. You can get them cheaper from china but I got them in 2 days from a US seller.

[jwcastle]

Thank you VERY much for the helpful tutorial. During the summer months when the temperature is high, I like to lower the hash rate slightly. Combining that with undervolt method makes my rigs run much cooler.  All of my rigs are running at ~130GH/s with each drawing ~170 watts at the wall.

Cheers!

[philipma1957]

MY 3 are doing 420 gh pulling 560 watts at the plug.   

  so that is 1.33 watts a hash at the wall……   stable being doing it for about 1 month.

1)low errors
2)low noise
3)low heat

[leptar]

Question for those that know...


when using potentiometers, besides the 10k adjustable value what else should we be looking at?

I am seeing huge fluctuations regarding wattage ratings from .08w to .3w...

26 or 28 AWG tinned plated stranded wire should be sufficient..


TIA.

[philipma1957]

Question for those that know...


when using potentiometers, besides the 10k adjustable value what else should we be looking at?

I am seeing huge fluctuations regarding wattage ratings from .08w to .3w...

26 or 28 AWG tinned plated stranded wire should be sufficient..


TIA.

if the .3w don't cost much more you can use them.

remember the oem resistors are smd very small in physical size. a big bulky oversized pot is not needed.

[mstrongbow]

I don't think it's possible to break anything with this mod, but in case you break something, I'm not responsible

Why undervolt the antminer s1 ?
Because with default voltage (1.1v), the chip has a very bad efficiency

What are the results ?
I wanted to achieve 0.85v on the asic. ( you can go at 0.75v if you want and share the result)

With this voltage my 3 antminer s1 are hashing at 140 GH/s each for 500 watts (166 watts per ant) (corsair AX1200i)  [1.19W/gh at the wall]
all my ants have less than 1 % of HW (0.95 0.5 0.3)

What is needed ?

• a pencil HB
• an antminer s1
• a multimeter (ohms meter and voltmeter)
  

How to ?

The following value works for an antminer with R3 resistor = 4.47 kOhms


When adding pencil on R3, the result will be a lower voltage on the chip, so it's difficult to burn anything by doing it.

Voltage :

• Turn off your antminer ...
• Check the R3 value  with the multimeter: it should be 4.47 kOhms (if not: the logic is the same but the next value are different)
• apply pencil on it
• Check the R3 value
• if R3 value is between ~2.8kOhms and ~3kOhms it's good, if not reapply pencil or remove it with your finger (it's not rocket science, so even if it's 3.1 don't loose your time ...)
• You can check the voltage of the chip with the voltmeter on the yellow things (the ant must be powered on) (~0.85v for me)

Freq (275 MHz):

edit /etc/config/asic-freq

        option 'freq_value'    '0A81'  #275M
        option 'chip_freq'     '275'
        option 'timeout'       '45'

Is there a need to ssh into the S1 and change the freq settings or am I not understanding correctly why the freq is posted in the OP???

Thanks!

[philipma1957]

mstrongbow

  it is two step.

 do the pencil mod or solder in a pot


then ssh the freq down a bit.    mine are 275 and 300.   for my 3  s-1's   two are  at 275 and 1 at 300.

  these freq's gave me the total of 420gh and 560 watts  and pretty low on errors.

[Rock53]

I have 10 S1 miners and I have 6 Thermaltake 1000w PSU's - I thought that I could run 2 of the miners on a single 1000w Thermaltake, but I can't.  I have an 850w Corsair and I can run 2 S1 miners.  None of my miners are overclocked.  Maybe by under-volting my miners, I can run 2 on one of the Thermaltake PSU's.  Will the drop in hashing be more than made up for in electricity savings by using 1 PSU instead of 2?  Does anybody have any other suggestions about why I can't run 2 miners on a Thermaltake, but can on a Corsair?  I don't want to spend any more money on buying more Corsairs'  Has anyone had this problem?  How did you fix it?

[elpres]

Have you tried using different PCI-E connectors?

[philipma1957]

I have 10 S1 miners and I have 6 Thermaltake 1000w PSU's - I thought that I could run 2 of the miners on a single 1000w Thermaltake, but I can't.  I have an 850w Corsair and I can run 2 S1 miners.  None of my miners are overclocked.  Maybe by under-volting my miners, I can run 2 on one of the Thermaltake PSU's.  Will the drop in hashing be more than made up for in electricity savings by using 1 PSU instead of 2?  Does anybody have any other suggestions about why I can't run 2 miners on a Thermaltake, but can on a Corsair?  I don't want to spend any more money on buying more Corsairs'  Has anyone had this problem?  How did you fix it?

I had your issue with fractal 1000 watt psu's.   you could buy this psu it runs 3  and is on sale

195 usd

http://www.newegg.com/Product/Product.aspx?Item=N82E16817438011&cm_re=evga_1300-_-17-438-011-_-Product

35 usd rebate form

http://images10.newegg.com/uploadfilesfornewegg/rebate/SH/EVGA17-438-011Jun17Jun2314yh62us.pdf

you can do the pencil mod and clock your gear to 300 freq hashes at 140-150gh pull 180 -200 watts.

[leptar]

thanks philipma1957..

anyone take it to .75v?

[Brassguy]

thanks philipma1957..

anyone take it to .75v?

I'm going to try to test the lower bounds in a couple days.

Here's all of the frequency settings I nave been able to find. The list isn't complete and is lacking some timeout numbers. I think I have the info for 200mhz and 193mhz. I just have to dig around.

Code:

#option 'freq_value'    '4f81'  #205GHs (16x)
        #option 'chip_freq'     '400'
        #option 'timeout'       '35'

        #option 'freq_value'    '5f05'  #202GHs (15.75x)
        #option 'chip_freq'     '393.75'
        #option 'timeout'       '36'

        #option 'freq_value'    '5e85'  #198GHs (15.5x)
        #option 'chip_freq'     '387.5'
        #option 'timeout'       '37'

        option 'freq_value'    '5e05'  #195GHs (15.25x)
        option 'chip_freq'     '381.25'
        option 'timeout'       '37'

        #option 'freq_value'    '4e81'  #192GHs (15x)
        #option 'chip_freq'     '375'
        #option 'timeout'       '38'

        #option 'freq_value'   '6c09'
        #option 'chip_freq'    '370.83'
        #option 'timeout'      '??'

        #option 'freq_value'    '5d05'  #188GHs (14.75x)
        #option 'chip_freq'     '368.75'
        #option 'timeout'       '38'

        #option 'freq_value'    '6b89'  #188GHs (14.75x)
        #option 'chip_freq'     '366.67'
        #option 'timeout'       '38'??

        #option 'freq_value'    '5c85'  #185GHs (14.5x)
        #option 'chip_freq'     '362.5'
        #option 'timeout'       '39'

        #option 'freq_value'    '5c05'  #182GHs (14.25x)
        #option 'chip_freq'     '356.25'
        #option 'timeout'       '39'

        #option 'freq_value'    '4d81'  #180GHs (14x) (default)
        #option 'chip_freq'     '350'
        #option 'timeout'       '40'

        #option 'freq_value'    '4c81'  #168GHs 
        #option 'chip_freq'     '325'
        #option 'timeout'       '45'??

        #option 'freq_value'	'0a81'	 #275
        #option 'chip_freq'	'275'
        #option 'timeout'	'51' or 45??
        
        #option 'freq_value'    '0a01' #267M
        #option 'chip_freq'     '267'
        #option 'timeout'	'53'

        #option 'freq_value'    '5102'   
        #option 'chip_freq'     '218.75'
        #option 'timeout'       '58'??

        #option 'freq_value'    '5082'   
        #option 'chip_freq'     '212.5'
        #option 'timeout'       '65'??

        #option 'freq_value'    '5002'   
        #option 'chip_freq'     '206.25'
        #option 'timeout'       '68'??

        #option 'freq_value'    '0781'   
        #option 'chip_freq'     '200'
        #option 'timeout'       '70'

        #option 'freq_value'    '4f02'   
        #option 'chip_freq'     '193'
        #option 'timeout'       '70'