Bitcoin Forum

Hey Forums,

Does anyone know a good undervolt/underclock settings combo for the Antminer S4?  While I am working out some hosting these things are heating up my already full rack @ the office and my HVAC is having a little issue keeping up.  I'm certainly ok with the hash loss to bring the heat down a bit.

how many do you have and what are your current settings?

Not sure the relevance on how many lol :)   But the answer is two, and running stock.

I have seen a couple people set 162.5MHz and .67V claiming to get 1,500gh at ~1,000watts.

I got my S4 in the mail yesterday. I will be attempting these setting tonight. I will let you know how it goes if youre interested.

How did your under clock go?

So... took a little longer to get up and running than expected but 162.5M @ .67V seems to be steady at 1,450-1,500GH @ 1,000-1,050Watts.

I will let it run for a couple hours to double check stability but seems to be good for now.

I'm interested in the best settings to under volt these as well. My first question is should this be broken down into two setting types one for 110 users like me and others she went the 220 route ? Would that make a difference in settings and strain on PSU … I'm getting close to ROI on my 4 and I want to downshift and make room for the mythical S5 possibly .

same here needs a good under volt electricity is going up in my area planning to increase 50% which is nuts.

With October 16th firmware, 175MHz/0700V from the wall around 1085W (230V)
hashing stable 1754GHash

You guys realize that if you're using anything newer than the Oct. 16th firmware you don't have voltage control, right? Bitmain disabled it starting with Jan. 29th firmware.

Are there any new options for this Undervolting?
Anybody an idea how the PencilMod (i brought my S3 from 0,7W down to 0,53W with the pencil) like on the S3 (https://bitcointalk.org/index.php?topic=771979.msg11609261#msg11609261) would apply to the S4?

Use the right firmware & you can adjust the voltage form cgminer, pencil mod not needed or relevant here.

Rich

Ok, thanks for the Info  :o ;D :D

Can u be more specific on details about how to do this??

And does it last a reboot??


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Best underclock using sept 04 2014 image

Running on 240 volts (In Australia)

Using Freq : 100 & Volt : 0670

I get around 980gh @ 640w - (Tested with a kill o watt)

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https://bitmain.zendesk.com/hc/en-us/article_attachments/200965819/s4sep26.img.gz

u'll need to unzip this & use hdd raw copy to image this to ur sd card (U'll need to take the sd card out of the miner & do this on ur pc)

This will give u undervolting again...

Now i know this uses an old cgminer & is known to have issues so do this..

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This will install Smit's low fan firmware (To keep noise to absolute min) & cgminer 4.9. It will also survive a reboot...

Connect to your S4 via SSH. We all know that username is "root", password is "admin". Also we all know that we need use PuTTY software

Then we get into /mnt/mmc1 folder:

Code:
cd /mnt/mmc1

Rename initramfs.bin.SD to initramfs.bin.SD.orig (or with any name convenient for you) to make rollback possible:

Code:
mv initramfs.bin.SD initramfs.bin.SD.orig

Then we can download those tho images for slow fans & cgminer 4.9

Code:
wget http://95.84.240.160:8080/s4_symlink/S4_cgminer_symlink_low_fan.initramfs.bin.SD -O initramfs.bin.SD


Now we are ready to download cgminer. Note that after above steps we have to put cgminer's files to /config/cgminer folder, otherwise mining will not start.

We can now download and put cgminer to the necessary folder with this code:

Code:
cd /config && wget http://95.84.240.160:8080/s4_symlink/cgminer_4.9.0_S4 -O cgminer && chmod +x cgminer

Now type exit & reboot ur machine.

Any problems please ask or pm..

PLEASE BE AWARE - The slow fan firmware should only be used at the underclocked & undervolted settings... U could start a fire if u use this at full speed!!

----------------------------------------------------------------------

UPDATE

If u can get the J7 board to set the voltages correct on startup (This requires a kill o watt or similar)

To do this u'll need to start & restart the machine till the kill o watt tells u the right voltage / watts...

The amount of restarts is random so just keep trying it till it sets right.

Old settings as above with J7 on the loose will give 640w

With the J7 running correctly it will be 600w, That's another 40w saving....

 The OP had asked about pencil mod and I was just making the point that you can adjust the voltage from cgminer so long as you have the right version, as you have comprehensively covered in your post above.

Rich

Cool thanks for the clarification