Author

Topic: 4 pin fan for antminer (Read 567 times)

newbie
Activity: 15
Merit: 3
June 07, 2018, 06:47:21 PM
#16
Yes voltage in is a constant 12v.
Intel's 4-wire PWM fan spec http://www.formfactors.org/developer/specs/4_Wire_PWM_Spec.pdf
Quote
3.3  Fan Speed Response to PWM Control Input Signal
The PWM input shall be delivered to the fan through the control signal on Pin 4 (see Section
2.1.4). Fan speed response to this signal shall be a continuous and monotonic function of the duty
cycle of the signal, from 100% to the minimum specified RPM. The fan RPM (as a percentage of
maximum RPM) should match the PWM duty cycle within ±10%. If no control signal is present
the fan shall operate at maximum RPM.
See Figure 3.

LOL. I tried it on my oldest S9 and once I cut the blue wires, the rear fan ran at full RPM and the front fan at 1320 RMP (I assume that was the minimum RPM). I got this early S9 used, so it's possible that those are not the original factory fans.

I think the simplest way to make these older S9s cooler is to replace the fans with the new ones Bitmain uses on the newest S9s... they seem to be much more efficient.

The one side effect of my experiment that may be useful info for others as well: I confirmed that the front fan has the lower RPM. At least on this specific miner... I have several different generations of them so I may check the others as well, but I assume this should be consistent.
legendary
Activity: 3822
Merit: 2703
Evil beware: We have waffles!
June 07, 2018, 09:06:02 AM
#15
Yes voltage in is a constant 12v.
Intel's 4-wire PWM fan spec http://www.formfactors.org/developer/specs/4_Wire_PWM_Spec.pdf
Quote
3.3  Fan Speed Response to PWM Control Input Signal
The PWM input shall be delivered to the fan through the control signal on Pin 4 (see Section
2.1.4). Fan speed response to this signal shall be a continuous and monotonic function of the duty
cycle of the signal, from 100% to the minimum specified RPM. The fan RPM (as a percentage of
maximum RPM) should match the PWM duty cycle within ±10%. If no control signal is present
the fan shall operate at maximum RPM.
See Figure 3.
newbie
Activity: 15
Merit: 3
June 07, 2018, 07:33:45 AM
#14
Maybe.
There are 2 control methods, one is no signal on Blue = full speed which in my book is the safest, the other is no signal = lowest speed. Looking up the fan specs should say which they are.

I've never played with the fans so just cut the blue on one fan and see what it does, you can always splice the wire back together if it slows down. Beyond that setting min fan speed to 100%  - should - force them to always run full speed.

Thanks - unfortunately, the specs for these fans are nowhere to be found... So I guess it's testing time.

I've read posts about manually setting the fan speed to 100% but it seems complicated with a lot of uncertainties so I'd rather go the hardware route.

How about the voltage in? Is my assumption correct that since the fans are controlled with PWM, the input voltage should be constant (always the full 12V)?
legendary
Activity: 3822
Merit: 2703
Evil beware: We have waffles!
June 06, 2018, 11:11:55 PM
#13
Quote
If I simply cut the blue wire, the fans should run at full RPM all the time, and since the miner will still receive the PWM signal from the fans, it will operate normally (won't assume fan failure and stop mining). Is this correct?
Maybe.
There are 2 control methods, one is no signal on Blue = full speed which in my book is the safest, the other is no signal = lowest speed. Looking up the fan specs should say which they are.

I've never played with the fans so just cut the blue on one fan and see what it does, you can always splice the wire back together if it slows down. Beyond that setting min fan speed to 100%  - should - force them to always run full speed.
newbie
Activity: 15
Merit: 3
June 06, 2018, 08:10:32 PM
#12
As for front/rear speeds, even Bitmain can't seem to make up their mind. As a power systems designer, personally I'd put the faster fan on the intake side to provide higher pressure airflow in to overcome resistance from the turbulence all the little heat sinks make. What might change is the noise.

Thanks for the info! Good to know. I know they have different fans, but I don't know yet which one is faster (can't find the specs for their fans - mine have NIDEC UltraFlo W12E12BS11B5-57 on the front and NIDEC UltraFlo W12E12BS11B5-07 on the back) and the UI doesn't tell you which one is front and which one is back.
newbie
Activity: 15
Merit: 3
June 06, 2018, 08:03:58 PM
#11
The 4 pin is not essential unless you want fan speed control. What others here said is correct, you want to meet the spec of the fan to replace. A 3 pin fan with same or similar specs will suffice you just won't be able to the control the fan speed.

It's too hot where I am and I'm trying to cool the miners as much as possible. Noticed that my old S9s (with the Delta fans) don't run the fans at full RPM even when the chip temps go over 100C. So I want to hack the miner to have the fans run at full speed all the time - I just want to make sure I understand what I'm doing.

I'm not an expert of fans, just trying to figure this out. Since these are 4 wire fans, I assume black = ground, red = input voltage, yellow = PWN (tach) out, blue = PWM input (speed control).

What I'm not sure about:

1. If I simply cut the blue wire, the fans should run at full RPM all the time, and since the miner will still receive the PWM signal from the fans, it will operate normally (won't assume fan failure and stop mining). Is this correct?

2. As the S9 uses PWM speed control, I also assume that the fan receives the full 12V input voltage on the red wire from the control board all the time, i.e. voltage is NOT used to control fan speed. If this is true, then ideas I heard about connecting the fans directly to 12V from the power supply should make no difference and this is unnecessary. Is this correct?
legendary
Activity: 3822
Merit: 2703
Evil beware: We have waffles!
June 06, 2018, 07:55:33 PM
#10
As has been said elsewhere here in far too many threads, from the s7 on up all Antminers require fans that deliver high-static pressure and yes that means LOUD ones. CFM is only a small part of the airflow spec and normal 'high CFM' fans only deliver spec'd airflow against zero back-pressure. Put them on a s7/s9 etc and airflow drops like a stone very quickly leading to an overheated miner.

I know this is an old thread, but found it looking for info on the fans. Do you know how it works specifically for the S9? Which fan needs to be faster - the front or the rear one?

I noticed the different fan speeds, so I assume the reason is to create either negative or positive pressure inside the miner, I'm just not sure which one. Also not sure if they are controlling the fans separately to create the different RPMs or together, and let the different RPM ratings of the front and back fans take care of the pressure difference.

Any insight into this would be appreciated.
1st, Kudos for recycling your question into an existing thread! Keeps the relevant info easier to find.
As for front/rear speeds, even Bitmain can't seem to make up their mind. As a power systems designer, personally I'd put the faster fan on the intake side to provide higher pressure airflow in to overcome resistance from the turbulence all the little heat sinks make. What might change is the noise.
newbie
Activity: 15
Merit: 3
June 06, 2018, 07:40:45 PM
#9
I believe the front fan needs to be faster, although the fans are practically interchangeable (?). I use the same spare fans for front and back and it seems to make no difference.

Thank you. Actually, the front and back fans are different (different model/part numbers). I don't think swapping them or replacing one with the wrong part number (as long as they move enough air) will kill the miner but may be non-optimal.
full member
Activity: 1022
Merit: 221
We are not retail.
June 06, 2018, 12:16:52 PM
#8
The 4 pin is not essential unless you want fan speed control. What others here said is correct, you want to meet the spec of the fan to replace. A 3 pin fan with same or similar specs will suffice you just won't be able to the control the fan speed.
full member
Activity: 538
Merit: 175
June 05, 2018, 07:30:05 PM
#7
Do you know how it works specifically for the S9? Which fan needs to be faster - the front or the rear one?
I believe the front fan needs to be faster, although the fans are practically interchangeable (?). I use the same spare fans for front and back and it seems to make no difference.
newbie
Activity: 15
Merit: 3
June 05, 2018, 06:08:53 PM
#6
As has been said elsewhere here in far too many threads, from the s7 on up all Antminers require fans that deliver high-static pressure and yes that means LOUD ones. CFM is only a small part of the airflow spec and normal 'high CFM' fans only deliver spec'd airflow against zero back-pressure. Put them on a s7/s9 etc and airflow drops like a stone very quickly leading to an overheated miner.

I know this is an old thread, but found it looking for info on the fans. Do you know how it works specifically for the S9? Which fan needs to be faster - the front or the rear one?

I noticed the different fan speeds, so I assume the reason is to create either negative or positive pressure inside the miner, I'm just not sure which one. Also not sure if they are controlling the fans separately to create the different RPMs or together, and let the different RPM ratings of the front and back fans take care of the pressure difference.

Any insight into this would be appreciated.
legendary
Activity: 3822
Merit: 2703
Evil beware: We have waffles!
October 30, 2017, 03:53:06 PM
#5
Can any 4 pin 4 wire fan work on antminers
NO!
As has been said elsewhere here in far too many threads, from the s7 on up all Antminers require fans that deliver high-static pressure and yes that means LOUD ones. CFM is only a small part of the airflow spec and normal 'high CFM' fans only deliver spec'd airflow against zero back-pressure. Put them on a s7/s9 etc and airflow drops like a stone very quickly leading to an overheated miner.
newbie
Activity: 24
Merit: 0
October 30, 2017, 03:48:49 PM
#4
I've got a bunch of pulled fans from S5 and S7 if you're looking for a stock replacement. If you're trying to make a miner quieter, good luck.

I have 1 Hashboard and 1 controller with 2 fans,
something has to be plugged in the fan sockets or it wont turn on
I have it in the lounge and its quite as a lamb
With an ordinary 500 watt power supply
blowing on the board
Its such a waste the fan on the supply goes nowhere so ive turned it on the hashboard
Its whats called open plan (there are no covers like a gpu miner)

Works a treat and decibels in the 40 and temp is 55
legendary
Activity: 3374
Merit: 1859
Curmudgeonly hardware guy
October 30, 2017, 12:09:32 PM
#3
I've got a bunch of pulled fans from S5 and S7 if you're looking for a stock replacement. If you're trying to make a miner quieter, good luck.
full member
Activity: 658
Merit: 118
October 30, 2017, 12:01:35 PM
#2
I'm not sure what you mean by "any", but you need to make sure you have the right specs on the fan.

I believe itsa 12v, ~3amp 120mmx120mm - could be wrong on the amp for the fan though.

https://www.banggood.com/6000RPM-Cooling-Fan-Replacement-4-pin-Connector-For-Antminer-Bitmain-S7-S9-p-1202844.html is the one that they sell on Amazon.
newbie
Activity: 24
Merit: 0
October 30, 2017, 10:29:47 AM
#1
Can any 4 pin 4 wire fan work on antminers
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