Official Pi-4 fan - screamy/whiny, and no apparent speed control?

Hi All,

I recently bought a Pi 4 and the official case and fan.

The fan is described as “* Fan speed control: Pulse width modulation control via user-selectable GPIO pin” but nowhere can I find the speed control described.

In my experience it comes on at the one speed when the set threshold is reached, and makes a hell of a screamy/whiny racket. You definitely know when it’s on.

Is the documentation not correct, am I misinterpreting it, or have I missed a step somewhere?

My desire is to have it turn on at a lower speed at a lower temperature, and ramp up as the temperature increases. If I can’t get it to run without the horrid noise it’s going in the bin.

Thanks,

Greig.

Got a photo of your connections? Have you enabled the GPIO Fan speed control in raspi-config?

Hi Oliver,

Unfortunately raspi-config doesn’t appear to offer fan speed control - only a temperature-based on-off switch. Are we missing a plugin or some other software component that extends this functionality?

  • Greig.
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Hmm maybe Raspberry Pi haven’t written a pwm driver yet.

Here’s one:

with regards to the original instructions pls read the product page and these are the setup notes i put together from my understanding…as there really is not much on the site at al…

if your fan is whining or sounds rattly then after you try the below and still have issue pls post back for assistance from admin …

5volt RED wire = pin 4
zero volt or Ground BLACK wire =pin 6
BLUE wire =pin 8 which is processor interrupt referenc GPIO 14.

there are four dos boxes on the screen…
this is the most confusing to a noob as we refer to people starting out into their rpi journey…

now when you follow the on screen setup instructions there is a question that asks
to which gpio is the fan connected
you must code this answer “gpio14” and save this and only change this if you connect the blue wire to a different board pin … but don’t change from the manufacturer default pin 8 pls…
the other boxes on the setup page are quite self explanatory

TIP: .as a self test set the fan to start at a low temp say 30 degs
set the temp trip points as the same set the fan speeds you can enter many times on one dos box before saving and editing and then rebooting and the fan will be set and governed buy your choices
next to change again or edit reopen the app and then edit as you wish…

so what you are basically doing ios forcing the fan to com on at low temp then next…
set the fan to turn off at 35 degs…after a short period the fab will switch of…then play with the numbers but never change the gpio pin setting play with the other three dos box choices as you like…
adjusting the device and testing for you self is a good learning experience…

is this making some sense to you now…yes its confusing…however now you have a further understanding…gpio references are not actually always the board pin numbers…and can be often re assigned…

pls try these out to help us out thx…

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Thanks Brian,

Do you mean the product page on the Core website, or the linked official Pi documentation? I’ve been through all I can find.

It’s definitely wired correctly and setup in raspi-config with the correct IO pin (as per the screen-grabs I posted earlier), as the fan turns on and off as the Pi heats and cools.

I don’t understand you here. Are you suggesting a space-delimited incrementing list of temperatures in response to the “at what temperature in degrees should the fan turn on?” prompt, at which the presumed PVM drive will ramp up the on-time?

I gave that a shot, but unfortunately only one value is accepted:

- G.

I’m starting to reach that conclusion - but the product’s documentation all seems to indicate it’s MEANT to do this.

It wouldn’t be the first time that Marketing’s gotten ahead of product development of course. I can only presume it’s on the back-burner somewhere. Until the Pi Foundation’s dev catches up with their marketing, I think I’ll need to use a third-party fan driver such as the one you’ve linked (thanks).

- G.

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just received my rpi 2 nite…set the degrees in a single figure 60…
60 min is really needs to be looked at as well…!! i can set my argon hat at 5 degs trip if i want…software issue…i`ll look at it this week my self…
i am going to fit my notura to it time permitting,just fit the heatsink and it will be good to run at standard clock speeds prolly get away with 700 not shure…

we should loo k at the fact that your device may well be faulty…the fan…???

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I doubt it. As the Pi seems to be sending sending full power, the fan’s running at full speed. That it’s noisy at full speed is something you generally expect of small fans, but if as a genuine Pi accessory it’s being sold as PWM control and it’s not working as advertised, then it’s not fit for purpose and I can request a refund.

But I thought I’d ask here first - and probably be asked to by the team - before I embark on that process.

- G.

Hi Grieg,

Sorry for the late reply, have just sent you an email regarding the next steps on a potential return. Hope this helps!

Thanks Mitchell, got it. Unfortunately it looks like I’m stuck with it.

I’ve been doing some more reading online, and it looks like the tiny fan is meant to make this annoying screaming sound. Have a listen here..

This is not helped by the poor (read as “non-existent”) airflow in the official Pi 4 case, which means the fan’s going to run for longer. (Just one review of it.)

My preferred case for quite some time has been the “strawberries and cream” look of the official case, but it seems with the Pi 4 I’m going to have to find another case. And bin this fan.

- G.

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Hi Grieg,

Actually, they did quite a bit more than just stick a fan in the official Pi case, and it’s a lot more effective than just going to town with a dremel and bolting one in the lid. Gordon Hollingworth (the guy that designed this) did a write up on some of the CFD and thermal design and testing here:

And I found some comments on the Pi Blog post from Gordon that indicate there won’t be a PWM driver any time soon, as his preference is for it to only run some of the time, and be silent most of the time.

Personally I have no issues with 55dB (it’s really very quiet by my standards), but if your goal is complete silence, a passively cooled case is definitely the way to go.

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