Haha, same at my side. I sent 5 dead S17 to Bitmain during October and now, more than half year later they sent me 1 working and two dead units. I'll repair them by myself.

Oh sorry, I forgot one much easier workaround. Just simply add any 3pin or 4pin CPU fan and leave it on the top of the miner running freely.

My friend's 0.25MW farm is about 0.09E/kWh and 95% customers decided to switch off and leave. My other friend's own farm with 0.07E/kWh is already switched off.

I wish you good luck, you will really need it, but I belive that 2019 will be S9 and similar profitable again with your energy prices and 2020 you will be overfilled thanks to another bull run.

Yes, this problem exist under light load or cold ambient temperature. Next release will probably fix it.

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Yes, the problem is that it expect TWO FANs. To overcome it, you can connect RPM pin from FAN1 with FAN2 on control board. Just connect pin with yellow wire with the same position at FAN2 position. Always do this when disconnected power - next pin is 12V which will permanently damage control board when connected to RPM yellow pin. (I did it.)

Next release should fix this problem.

Hi,

AFAIK all S9 except very old ones can run any asicboost firmware (either original bitmain or BraiinsOS). You can check kernel log for control board type. If it is Xilinx, it can run asicboost, if it is Altera it is not supported yet.

Really good job. Switched my miners to Slush. Thanks!

I still do not understand why we should pay fee, when another FW with the same functionality is available for free?! Your FW can set only voltage and frequency, for the cost of fee, so where is the advance?

For those who want to keep it fanless I can compile their version for free also.

here is it:

https://bitcointalk.org/index.php?topic=4491904.0

Just try what your PSU accept. It has overload protection, so in case it will be overloaded, it will shut itself off.

Fixed freq FW adjust voltage depending on frequency. Higher freq means high quality of chips, so FW will set 8.8V per chain. If you use 600MHz, it will set 9.3V for the chain, because it expect lower quality of chips. I compiled binaries which do not respect quality of chips and up to 675MHz will set declared voltage (eg 8.4V). 675MHz and more will force voltage to be at 9.4V for easy OC without copying new binary.

So, for underclocking, copy bmminer with 840mV (8.4V) to your /usr/bin directory. It will force 840mV for all frequencies up to 675MHz.

Based on my experiences with Antminer D3, some boards works better at higher frequency at the same voltage level. The correct frequency was only one unique frequency. Lower didn't work and higher didn't work also. It is probably because of chained chips are dividing voltage between each chip group a bit different at each frequency.

Check kernel log for "setting working voltage" where you will see which working voltage it applies with autofreq or with fixed voltage. Autofreq boards has different voltage for each board while fixed freq sets the same voltage for all boards. I was shocked, that at 600MHz fixed firmware applied 9.3V for the chain and at 650MHz it undervolted to 8.8V.

All miners have safety built-in cut-off temperature (can be disabled), where miner stops and cools down. Maximum speed depends on chip and VRM temperature. My own experience is that S9 survive temperatures over 110C at chips for 24/7 operation. For those who do not agree just looak at Antminer R4 which is "silent" and always works at 110-115C. Anyway, based on earlier S5, chips they unsoldered themselves under full load, so temperature exceeded 200C. They worked again when resoldered back.

So back to temperature: It is not possible to check VRM temperatures, but first batches of S9 was without heatsink on VRM. They worked well at standartd frequency, so newer batches should work well when OCed. My opinion is that only VRM temperature is the only limit of OC level, so keep temps as low as possible.

Unreliability of S9 leading to lost chips is caused by unpredicted behaviour of chips in serial chain. This will cause temporary overvoltage of some chips which will destruct them. Only one dead chip can make whole board stop hashing or prevent detecting of ASICs. Unfortunatelly, S9 still hasn't reliable overvoltage protection.

I do not agree you will shorten life of your miner in any measureable way. Chips are deeply under its maximum performance, only one unknown is VRM. Anyway I agree that even unmodified S9 is not reliable. Hope my opinion will help you.

FYI: Alexander1560 from the video claims he has working S9 at 850MHz.

You also got some points, hope someone will be able to modify source code to accept different freq or voltage control for each board or much better select voltage from menu.

sure, here is tutorial video

https://www.youtube.com/watch?v=eD5F_KHkkqQ

I have small revolution for you. I found recent tutorial on youtube. Everything works, fans can be disabled, voltage can be modified... here is the link:

https://www.youtube.com/watch?v=eD5F_KHkkqQ

Hi, I just made some binaries for our Antminers S9. It works also with R4. It might work with T9, but I didn't test it.

I decided to compile bmminer from official bmminer GitHub repository and since I am no programmer, I am unable to pass per-board parameters, so all binaries have fixed voltage for all chains, it requires only one fan and 3000 RPM max is enough (good for R4 or silent fans).

All versions have treshold of 675MHz+ where voltage is maxed at 9.4V for the chain (0.4476V at chip) so you can easily switch between low speed efficiency and maximum overclock. I can confirm, that 14TH/s machines can easily OC to 18TH/s+, but require two APW3 PSUs (it will draw about 2kW at 18TH/s).

Please note that 14TH/s machines are selected by bitmain and they have better efficiency, so they require lower voltage at 14Th/s compared to 13.5TH/s. Typical 14TH/s machine has 8.8V each chain.

Miner reports its version with voltage. Please consider your skills, I am not responsible for any damage you did.

How to?

Download correct binary of target voltage you wish to use.

1) Run Putty and connect to your miner IP.
2) Log in, L/P: root/admin
3) run command in Putty: /etc/init.d/bmminer.sh stop
4) now, you stopped mining and released bmminer binary to be renamed

5) Run WinSCP, connect to your miner IP address.
6) change remote directory to /usr/bin
7) rename bmminer to bmminer.old
copy new bmminer to remote dir. Double check permissions of new file - must be executable! Set attributes if not.

9) go back to putty and run command: /etc/init.d/bmminer.sh restart
10) well done! Watch your system log for correct voltage set by bmminer. You are mining at voltage you set.

TIPS:

1) install firmware with fixed frequency first before you upload new binary. Fixed frequency firmware allows you to modify fan speed at config page.
2) frequency settings are at "hidden" page. It is at <miner ip>/cgi-bin/minerAdvanced.cgi
3) most of S9 has mixed quality of boards, so sorting of hash boards will help you to keep best settings for each miner (require 2 or more machines)
4) lowest voltage I tested is 8.2V, but it is unstable even with low frequency, so play with it to find your sweet pot

Is it legit? Am I scammer? No, I am old member RadekG, but my account was hacked and now some scammer is using my identity. Just check old RadekG messages (hardware) and new about shit. In case you feel something is wrong, please update with fresh firmware, it will revert miner to factory defaults.

Please note, this modification requires basic windows + linux skills.

Big thanks to Alexander1560

here is the link:

https://drive.google.com/open?id=1mh3mDZ_LxkeE9D0Mx40-2f4YGhR9r57f

really good work. Can you also compile it for Xilinx? It will be really helpfull with S9...