Antminer S5 - Underclock - Undervolt - Best J/GH

[RichBC]

My favoured solution would be an adjustable Server PSU, trouble is not much information exists on which ones can be easily adjusted. The RC guys are very hot on voltage adjustment but they are mostly interested in increasing the voltage. This is often easier as you can use an adjustment to the sense voltage to trick the PSU into increasing it's voltage.

The Bitmain PSU has an adjustment and has been reported to be adjustable from 11.5V to 12.6V This is useful but not really low enough for max underclock.

I have played with an HP DPS600, this can be mad to go 10.56V but unfortunately as you turn the volts down the Power you can draw drops and again is not ideal. (data somewhere back in this thread)

I am sure there will be some wide range adjustable Server PSU's however at the moment I do not know which ones? Which is why I have used a separate Buck converter, not ideal, not as efficient, more wires, but very adjustable and enables you for a small additional cost to use an existing PSU.


Rich

[adaseb]

My favoured solution would be an adjustable Server PSU, trouble is not much information exists on which ones can be easily adjusted. The RC guys are very hot on voltage adjustment but they are mostly interested in increasing the voltage. This is often easier as you can use an adjustment to the sense voltage to trick the PSU into increasing it's voltage.

The Bitmain PSU has an adjustment and has been reported to be adjustable from 11.5V to 12.6V This is useful but not really low enough for max underclock.

I have played with an HP DPS600, this can be mad to go 10.56V but unfortunately as you turn the volts down the Power you can draw drops and again is not ideal. (data somewhere back in this thread)

I am sure there will be some wide range adjustable Server PSU's however at the moment I do not know which ones? Which is why I have used a separate Buck converter, not ideal, not as efficient, more wires, but very adjustable and enables you for a small additional cost to use an existing PSU.


Rich

Do you mind posting a photo or your setup? Just want to see if it looks messy

[RichBC]

Do you mind posting a photo or your setup? Just want to see if it looks messy

Away from Home until after the new Year, and not using the Buck Converter at the Moment as with the improved Exchange rate I am running the S5 flat out.  However I will put it together again and take a photo when I get back.

Rich

[Logan5]

can 2 s5 boards be set up in series maybe? the reason im asking is my solar panels are putting out 20 volts.

[RichBC]

can 2 s5 boards be set up in series maybe? the reason im asking is my solar panels are putting out 20 volts.

Would not do this as it will cause all sorts of problems with grounds & the controller interface etc.

I would advise using a Buck Converter to convert the 20V to 12V, however you will also have a problem when the sun goes in and you loose the Power?


Rich

[Logan5]

[quote authorjavascript:void(0);=Logan5 link=topic=1151460.msg13774847#msg13774847 date=1454600923]
can 2 s5 boards be set up in series maybe? the reason im asking is my solar panels are putting out 20 volts.

Would not do this as it will cause all sorts of problems with grounds & the controller interface etc.

I would advise using a Buck Converter to convert the 20V to 12V, however you will also have a problem when the sun goes in and you loose the Power?


Rich
[/quote]

rich thank you for all your input on this subject here, in the s7 thread and over on https://fanbitcoin.com/index.php?topic=771979.0;all about the s3

i figured the controller would need to be kept at a lower voltage as for the cloud passing by issue i have 7.5KW / 50 153 watt panels im trying to use for mining and i should have plenty power to do a little buffering.

yes i have a couple of 12 amp buck converters coming in tomorrow but the 40amp one linked here isnt available any longer and other high amp ones for a cheap price has been hard to find.

as for evening hours i plan to switch to house current for profitable miners like the s7 and on that note can they be underclocked / under volted the others7 thread seemed like no one has tried...  in the s3 thread the pencil mod / adding resistors to change the buck regulator is cool and all but what you did using the digital pot is more what im thinking and FYI my C1 i just lowered to 650 in the advanced tab and 150 clock and it like .63 so kinda intresting...  

[RichBC]

as for evening hours i plan to switch to house current for profitable miners like the s7 and on that note can they be underclocked / under volted the others7 thread seemed like no one has tried...  in the s3 thread the pencil mod / adding resistors to change the buck regulator is cool and all but what you did using the digital pot is more what im thinking and FYI my C1 i just lowered to 650 in the advanced tab and 150 clock and it like .63 so kinda intresting...  

Happy to have been of some help. Would it not be easier to just have  grid tie inverter and run the Miner in the conventional way, and then just keep track of the Solar Power you have generated & Power off the Miner for the right amount of Hours so that you were only effectively using solar power for mining?

Have not seen S7 Undervolted successfully yet and results will depend on batch. The 162 chip versions will be able to accept reducing the voltage as they are pure string design. The 135 chip systems have a Buck converter controlled by a PIC microcontroller, however although there has been some discussion noone has reported doing the work to fully understand the Pic / Digital Pot arrangement and come up with some Mods. which I am sure will be possible and enable undervolting.

Unfortunately I do not have an S7 otherwise I would play with this. Which batch / version do you have?

Rich

[Logan5]

I think i have a s7 batch 8, IDK yet for sure but it came clocked at 700... i have it, 2 s3's, a C1 and a s5 that im clueless what board is in ATM too.
yes a gridtie does make a lot of sense but my panels aren't UL approved and here in the USA they have to be is my understanding.

BTW in s7 batch 10 they say Rated Voltage: 11.60 ~13.00V

so far the s5 looks to me like it may be my best option to burn the 7.5KW undervolting using 2 12 or 15 amp buckconvters each connected to 1 board.
do you have any idea what will happen if the amps needed aren't available?

[RichBC]

I think i have a s7 batch 8, IDK yet for sure but it came clocked at 700... i have it, 2 s3's, a C1 and a s5 that im clueless what board is in ATM too.
yes a gridtie does make a lot of sense but my panels aren't UL approved and here in the USA they have to be is my understanding.

BTW in s7 batch 10 they say Rated Voltage: 11.60 ~13.00V

so far the s5 looks to me like it may be my best option to burn the 7.5KW undervolting using 2 12 or 15 amp buckconvters each connected to 1 board.
do you have any idea what will happen if the amps needed aren't available?

yes 700MHz will be batch 8 or 9, with 135 Chips & the Buck Converter.

Not having enough Amps is not a good idea. The voltage will drop and the Miner will stop mining, then the voltage will rise again, miner will reboot and the cycle will repeat. Could easily harm the miner.

Rich

[Logan5]

can any of you DC power experts tell me why when i hook up a buck converter outputting 12 volts and what should be plenty of amps my meter goes black and the board isnt powering up, im even running the control board and the other hashing board off a real power supply and turned it on afterwards...

i tried another brand of buck converter too.
only thing i can figure why my panel meter goes black is it's sucking the voltage down under the 6v min but why is the billion BC question.

Thanks in advance.

[RichBC]

can any of you DC power experts tell me why when i hook up a buck converter outputting 12 volts and what should be plenty of amps my meter goes black and the board isnt powering up, im even running the control board and the other hashing board off a real power supply and turned it on afterwards...

i tried another brand of buck converter too.
only thing i can figure why my panel meter goes black is it's sucking the voltage down under the 6v min but why is the billion BC question.

Thanks in advance.

What do you mean by "meter goes black"? What range have you got the meter on / is it ok measuring other voltages?


Rich

[Logan5]

thanks for the quick reply rich, im such a idiot!!! it's just a panel amp / volt / watt meter that has a range of 6 to 100 volts and 100 amps i think but i found my problem, i started thinking maybe 1 of my 3 wires going to each side of the molex connector may be swapped around and no i was dumber than that!!!

i had the positive and negative reversed and i cant believe i didnt burn out the board but im testing on a s3 b4 i get brave enough to try my s5 or s7.

it's running fine ATM on a drok 8-12 amp buck at 150 clock since this buck is so low amp but at least it's not a dead short now LOL

[RichBC]

Good result, glad nothing got damaged, we all have these moments.....


Rich

[VRobb]

<snip>
i had the positive and negative reversed and i cant believe i didnt burn out the board but im testing on a s3 b4 i get brave enough to try my s5 or s7.
<snip>

Well I can tell you that if you swap the +/- on the S7 board you will indeed get a magical puff of smoke and need to buy a new one...   Not that I'd have any first-hand knowledge of this.