Fan curve / programmable fan behavior

[omniavatar]

Hey, thanks for a very useful application! I'd love it if it had a way of creating a fan speed curve. It wouldn't even need to be a graphical interface, but simply a logic like:

"Turn on fan at 50 celsius, then linearly increase speed until hitting 100 % at 90 celsius."

This would be great, because it would enable limiting fan speed at insignificant temps, while making it possible to ensure sufficient cooling when the CPU really starts to heat.

I'm not much of a programmer, but something like this should be simple to implement. What do you think? I could even try to do it myself, but I've no idea how to go about compiling and modifying the program. :)

[zocker-160]

Hi @omniavatar ,
thank you for your interest and for reaching out!

TL;DR: unlikely going to happen sorry :(

This suggestion has already been brought up in the past (see #14) and at first I also thought this cannot be too hard to implement, but sadly so far it has not gotten anywhere because it is not as easy as it sounds.

There are 3 main reasons:

1. The main issue is that the fan control interface exposed by the thinkpad_acpi driver, does not allow for fine fan speed control, but rather just has a few speed modes that you can set. Because of this any simple linear fan curve will be very annoying as it can happen frequently that the temperature is exactly between two modes switching back and forth.

2. Laptop CPUs tend to fluctuate and spike a lot in temperature, meaning that without any damping logic, any short CPU load is going to kick the fan into high gear, which is annoying, but not trivial to solve in a good way, as one has to take the duration of such a spike into account.

3. Instead of reinventing the wheel, good and maintained fan control software for ThinkPads already exists like this one here: https://github.com/vmatare/thinkfan

And finally given the mission critical nature of fan control (can cause hardware damage if not done properly), I don't think it is suited for a small toy project like this one which I did in an afternoon, because I just wanted a simple graphical way to control the fan speed on my ThinkPad.

[omniavatar]

Thank you for not only replying, but also for explaining the issue!

So, it's obvious solutions that work on desktops cannot be applied with laptops. Different beasts and all that. To hypothesize my ideal solution within this framework, I think I'd have the fan start and go into the lowest speed mode at a certain temperature, let's say 50 C, then ramp up through the following modes in correlation with the temperature.

I'll take a look at Thinkfan and see if I can figure it out. I'm still new to the Linux way of things, and so drift towards the GUIs as a crutch. :)

[zocker-160]

I also do prefer GUI solutions, this is actually one of my main reasons for creating many of my Linux applications. UX is important and it does lack in the Linux space.

Fan control however is something that I think belongs to a system process with a GUI configuring said process.
Letting the GUI application run as Admin like it is very common on Windows for system critical applications, is IMO not the right approach.

So in this case, the right way to go would be to create a GUI for setting up and configuring thinkfan, making it easier to install and set up, instead of reinventing the wheel.

I wanted to do that one day, but currently I don't have the time to do it.

[omniavatar]

If you ever wanna do it again and could use an avid beginner programmer in your team, hit me up!