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I'd like to control my fan's speed (to make it more silent under heavy load). I disassembled a Laptop to build a custom PC, fitted a gigantic 9x9cm tower cooler with a Noctua fan on it to absorb the CPU's and GPU's heat, so realistically the fan does not need to run at full speed ever. I am not sure what is currently controlling the fan speed, but it ramps up and down or stands still depending on the usage (temperature or cpu load? - I don't know.)

I tried everything from this thread, but I keep failing to detect the fan. How to control fan speed? I have a 3 PIN header, so not a pwn controlled one, but the voltage can be adjusted to make the fan stand still or spin slow to fast. So I can tell by its behaviour and a multimeter which reads 2,5V on standstill and 5V on max power.

Now I want to take control of the Voltage on that fan header.

There is no option to do this in the BIOS, although it may be outdated. I tried contacting Chiligreen, but there seems to be no way to do that. Bios Version is 1.04.QUA EC Version 1.07 Build Date: 09.02.2011

Just to make it clear, I have no thermal issues at all, my system is running nice and cool. You can find a picture here, so you can imagine why I want to slow down my fan.. Link to the picture

Thank you in advance, guys!

I am running Ubuntu 21.10 64-bit Gnome Version 40.4.0 Wayland

Hardware model: "A15HV01" aka. chiliGREEN Platin TS Intel® Core™ i3-2330M CPU @ 2.20GHz × 4 Intel® HD Graphics 3000 (SNB GT2)

viktor spett
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  • IDK if there's a tool for drive fan speed control.... but have you tried setting another cpu power governor ?, there are some tutorials talking about that. Tip: you can make use to $ watch sensors also and edit crit/hyst temp values.... – Matthias Lenmher Jan 03 '22 at 15:02
  • Thank you for your idea, after a jump into the Google rabbit hole, I assumed, that I would rather not change the CPU power governor without knowing what I am doing. It is currently set to schedutil (default value). But I read about thermald in the same arch wiki article and want to give it a shot. However, for me, no default thermal-conf.xml was generated. Honestly, I am a bit scared to create one, as I don't want to mess with all the thermal throttling settings, that I have no idea of. Is there a way to only change the fans' behaviour from the defaults using thermald? – viktor spett Jan 04 '22 at 10:47
  • What I have found out, is that /sys/class/thermal/cooling_device0 is my fan, but I have no idea, how I can control it. – viktor spett Jan 04 '22 at 10:59
  • ok, lets see: if you are using schedutil gov scheme, you are jumping about fast threshold response factor (these gov doesn't help with measuring, just fast responsive signals and can't take control bout temps,it's a big warning bout that.). try to use conservative when u just are using some office use or web browsing, and jump over schedutil when u rlly rlly need some fast cpu response (but caution with temps) – Matthias Lenmher Jan 04 '22 at 16:32
  • In other words: just switch over cpu governors =). if you still need to set a custom value in fan spinning sensors, u must bougth some physicalls for u. it comes with potenciometers that you can regule at you demand – Matthias Lenmher Jan 04 '22 at 16:35
  • So after I couldn't figure out thermald I tried nbfc, with no success. It seems nothing I try can detect my fan. My problem is not, that my CPU or GPU gets too hot. Under typical usage, it's between 40-60 degrees. My issue is, that my fan ramps up to the maximum value as soon as my CPU load raises and surpasses, idk like 65 degrees. But this has no effect on my already very cool tower, but is very loud to no benefit. So to recap: My fan is controlled by something, but I don't control that something.. Like right now, it doesn't even spin (CPU usage 11% temp 48C). – viktor spett Jan 04 '22 at 17:30
  • I emailed Chiligreen´s support (the Laptops manufacturer), maybe they can help with a BIOS update or something. – viktor spett Jan 05 '22 at 13:12
  • Lol they auto declined my email, Ill update this question later to be more specific.. – viktor spett Jan 05 '22 at 13:37

1 Answers1

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The original CPU-fan would turn slowly with 2.5V and would cool the system down at low load. At some point the controller/bios on the mainboard detects a rising temperature and set the speed to maximum. The functionality is not made for such a big fan.

With this gigantic cooling-system you do not need a regulation of the fan-speed, one setting will do the job.

This means, you have to see where you can get +5V from the mainboard and use some wires (Ground and +5V) to connect them with a little PCB, where you can add a resistor to reduce the voltage. Hole grid PCB: https://www.mikrocontroller.net/articles/Lochrasterplatine

If the current of the fan is 100mA and you need a voltage drop of 2 volt, then you need a 20 Ohm resistor. R=U/I

You can find cheap adjustable StepDown-Voltage regulator on eBay. A linear voltage regulator would work too, but he would generate a little bit of heat and they have mostly 2 volt drop on the inner resistance. So if you need 5V, then they need 7V or more to deliver the 5V.

MikroPower
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  • Thank you very much for your input. I might go down this road, but really I was hoping that I would not need a new voltage regulator when my motherboard has one built in. I will wait a bit longer maybe someone knows how that fan header can be controlled after all. – viktor spett Jan 10 '22 at 06:31
  • Sorry, but the possibility that you find someone who have modified a laptop-mainboard so that it is useable as desktop-PC, this is extremely low. But you found me. That someone have changed the cooler and try to use the onboard-regulator for it, this possibility is close to zero. They will not create bios-update for you, because it is not made for a custom fan. The voltage regulator is the fastest and cheapest solution. You can add a NTC in the feedback of the voltage-regulator to increase the fan-speed if he gets hotter. – MikroPower Jan 10 '22 at 19:07
  • Well looks like this is the way I’ll need to go :) I hope I can bother you with questions if I get stuck somewhere but should be nice and easy. Ill pock up som of the things when I have time. Thank you again. – viktor spett Jan 15 '22 at 07:23
  • Of course you can. It locks like you can not send me a message directly, but maybe as an answer here would work too. – MikroPower Jan 15 '22 at 21:46