[SOLVED] is it possible to run a group of fans while maintaining the same speed ratio? i.e. when one fan changes, the other also changes (e.g. 1200 1000; 1400

Grealish01

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sorry could you tell me how many rpm the curve of a be quiet dark rock pro 2 is adjustable (because on pcpartpicker it gives me only 1500 RPM speed instead on models like the noctua NH-D15 it tells me 300-1500 RPM? second question: is it possible to make a group of fans change the speed in the same way as the others? I explain better if I have the be quiet that varies the speed according to the temperature of the CPU, I can vary the speed of its fans to automatically vary the other fans close? for example if the heatsink goes to 1000 RPM I would like one fan to go to 1200 and the other to 800, then if the be quiet goes to 1100 RPM the other 2 fans automatically go to 1300 and the second 900 RPM Is this possible?
 
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I think you're overthinking this fan thing.

Fans really only have a couple of purposes:
  1. TO move air across some fin arrangement. Either a liquid radiator, or the fins on an air cooler.
  2. Move air through the case. Cool air in, warm air out.
And hopefully, do so as quietly as possible.
I'd think having Fans #2 and 3 dependent on what Fan #1 is doing would be conterproductive. If there is no need for 2 and 3 to spin up at a particular moment, then why have them do it?

kanewolf

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sorry could you tell me how many rpm the curve of a be quiet dark rock pro 2 is adjustable (because on pcpartpicker it gives me only 1500 RPM speed instead on models like the noctua NH-D15 it tells me 300-1500 RPM? second question: is it possible to make a group of fans change the speed in the same way as the others? I explain better if I have the be quiet that varies the speed according to the temperature of the CPU, I can vary the speed of its fans to automatically vary the other fans close? for example if the heatsink goes to 1000 RPM I would like one fan to go to 1200 and the other to 800, then if the be quiet goes to 1100 RPM the other 2 fans automatically go to 1300 and the second 900 RPM Is this possible?
With motherboard only hardware, I think the answer is no. The logic to associate fans does not exist in any BIOS that I am aware of. I don't find any aftermarket controllers with logic like that.
It might be possible to carefully choose fans, that have relative speeds with the same input voltage and then varying the input would change all of them. But if you suddenly wanted fan#3 to behave differently, that would not be possible.
There might be an Ardunio or PI Zero project to do what you want.
 
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Grealish01

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With motherboard only hardware, I think the answer is no. The logic to associate fans does not exist in any BIOS that I am aware of. I don't find any aftermarket controllers with logic like that.
It might be possible to carefully choose fans, that have relative speeds with the same input voltage and then varying the input would change all of them. But if you suddenly wanted fan#3 to behave differently, that would not be possible.
There might be an Ardunio or PI Zero project to do what you want.
as far as the be quiet dark rock pro 4 is concerned, how much is the speed of its 2 fan adjustable?
 

falcon291

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The fans in your computer are controlled by the mainboard so BIOS. Depending on your mainboard brand there are also applications available these control the speeds of the fans without entering BIOS.

And the fans use the temperature (mainboard or CPU) as the input to change the speed of the fans and if your mainboard has enough fan headers, you can adjust each of the fan speed independently. I did that because some fans were low speed and silent, so they can work a hundred percent all the time and some fans fast but also noisy in higher speeds, so I set them to work 30 percent and when speed increases 50C I want them to work % 100.

So, the answer to your question: No, you cannot set them work following other fans' speed.

But yes: Anyway, if CPU temperature increases, so will mainboard speed increases, and so the board fans will follow.
 
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Grealish01

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Le ventole del tuo computer sono controllate dalla scheda madre, quindi dal BIOS. A seconda della marca della tua scheda madre, sono disponibili anche applicazioni che controllano le velocità delle ventole senza entrare nel BIOS.

E le ventole usano la temperatura (scheda madre o CPU) come input per cambiare la velocità delle ventole e se la tua scheda madre ha un numero sufficiente di intestazioni delle ventole, puoi regolare ciascuna velocità della ventola in modo indipendente. L'ho fatto perché alcune ventole erano a bassa velocità e silenziose, quindi possono funzionare al cento per cento tutto il tempo e alcune ventole sono veloci ma anche rumorose a velocità più elevate, quindi le ho impostate per funzionare al 30 percento e quando la velocità aumenta di 50 °C voglio che lo facciano lavoro % 100.

Quindi, la risposta alla tua domanda: no, non puoi farli funzionare seguendo la velocità degli altri fan.

Ma sì: in ogni caso, se la temperatura della CPU aumenta, aumenterà anche la velocità della scheda madre e quindi seguiranno le ventole della scheda.
i
I would like to realize how many revolutions the be quiet dark rock pro 4 can go in a normal situation (surfing the internet, etc.) so as to adjust the setting of the other fans
 
second question: is it possible to make a group of fans change the speed in the same way as the others?
With Gigabyte motherboard it is (sort of) possible. Within the example you wrote you would need to set in BIOS input sensor for all those fans to CPU and then make the fan curves in such way to achieve desired speed ratios. It's not exactly one fan speed following the other, but the end result should be close enough to what you want to achieve.
Not sure though if motherboards of other manufacturers have such ability.
 
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USAFRet

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I think you're overthinking this fan thing.

Fans really only have a couple of purposes:
  1. TO move air across some fin arrangement. Either a liquid radiator, or the fins on an air cooler.
  2. Move air through the case. Cool air in, warm air out.
And hopefully, do so as quietly as possible.
I'd think having Fans #2 and 3 dependent on what Fan #1 is doing would be conterproductive. If there is no need for 2 and 3 to spin up at a particular moment, then why have them do it?
 
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Solution

Grealish01

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I think you're overthinking this fan thing.

Fans really only have a couple of purposes:
  1. TO move air across some fin arrangement. Either a liquid radiator, or the fins on an air cooler.
  2. Move air through the case. Cool air in, warm air out.
And hopefully, do so as quietly as possible.
I'd think having Fans #2 and 3 dependent on what Fan #1 is doing would be conterproductive. If there is no need for 2 and 3 to spin up at a particular moment, then why have them do it?
Yes you are right. actually i would like to understand what is the adjustment curve of the be quiet dark rock pro 4.
 

falcon291

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I would like to realize how many revolutions the be quiet dark rock pro 4 can go in a normal situation (surfing the internet, etc.) so as to adjust the setting of the other fans
As USAFRet wrote you are overthinking. CPU and mainboard temperatures are directly linked. CPU temperature changes a lot quicker, but mainboard temperature follows. But CPU temperature fluctuates a lot more, mainboard temperature constantly rises and falls. So even what you requested is possible, it would not be something we like.
 

Paperdoc

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Virtually ALL computer fans - case vent or CPU cooler - can be run over a range of speeds up to their max. So the spec they show always tells you the max speed, and the real minimum speed is always zero. But more important is the minimum speed you can set it to run without risking it will stall. Once the fan does stall, it will NOT re-start until its supply Voltage (or PWM signal) is increased significantly to overcome static friction for starting.

That automatic fan speed control system on the headers of your mobo does three things for this. One is to START the fan at boot time at full speed to be sure it does start up, then reduce its speed to what is needed. Another is to limit the minimum speed it sends out so that the fan will never stall. Another is to monitor the fan speed signal and detect a stall if that happens. If it does, the fan is re-started at full speed, then slowed down again. If that attempt to re-start fails, the mobo puts a warning message on your screen to alert you to total failure of that fan. So, knowledge of the minimum speed spec is useful only if you are trying to customize that limit in the configuration of your fan's header.

OP, you are making a common error. You focus on fan SPEED. In fact, what is important is AIR FLOW generated by the fan, but that is really hard to measure. Moreover, the mobo headers do NOT care what the speed is at all - they don't even look at that info to do their control job. Their real focus is TEMPERATURE as measured at a sensor. The CPU fan controls are based on temp inside the CPU chip with a sensor built into the chip. The SYS_FAN or CHA_FAN headers use a different sensor on the motherboard to guide cooling of the entire mobo and case. Each system tell its fan to change speed to whatever it takes to keep the TEMPERATURE at its sensor on target. It does NOT try to control to a speed target or to an air flow target - only looks at measured temperature and manipulates fan signal to achieve that.

What an individual fan does in response to its signal depends on what the fan is designed to do. Given the SAME set of signals from a header, different fans will run at different speeds and generate different air flows. All of that contributes to overall heat removal to achieve the temperature target. IF you connect two or more fans to the SAME signals using a fan Splitter or Hub from one header, they all will respond this way. (You can also get this result if you have fans connected to different headers BUT each header is configured to do exactly the same thing.) Now, IF all the fans are the same, they WILL run at very similar speeds.

You can set up different groups of fans by connecting them to different fan headers and custom setting each header's configuration. But in automatic control mode the ONLY variable they can respond to is a temperature sensor. On some mobos there are extra sensors devoted to particular mobo components, but that's not what you seem to be seeking. There are no mobo fan control systems that allow you to specify that one header will change its output to fans based on the speed of a different fan header.

You appear to be thinking that you can predict from the speed of one fan what the proper speed of a different fan ought to be. That is a form of what's called feed-forward control strategy: predicting a system's needs based on a model with no consideration of actual result. What IS built into a mobo is a feedback system. It uses the RESULT of its fan control decisions on a REAL measurement to decide on any possible adjustment to flow of cooling air produced by the fan. That measured variable is the TEMPERATURE inside the CPU or on the mobo, and that is the REAL aim of the system - to keep the component temperatures in a safe range.
 
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