bizarre laptop fan behaviour

[GreyGeek]

More than likely if sensors does not show the fan speed then I suspect using pwmconfig would have no effect because lm-sensors is not detecting fan speed. It can not change what it does not detect. My kernel logs show that during boot up the fan control is set to "automatic". I do not know what that implies, but on my system the fan seems to be generally off unless either the GPU or the CPU temp begins to rise, and then I can feel a gentle breeze from the fan exhaust port. It becomes forceful if the temps exceed 60C or so, but the fan is never noisy. I suspect that it is probably under BIOS control.

As far as running pwmconfig, I wouldn't. If lm-sensors was able to find your fan it would have set up a default pwmconfig conf file which would be used to set virtual params in /proc and which you would be able to adjust using pwmconfig. I'm just guessing, though. Like the old saying says, "If it isn't broken then don't fix it". Your fan is working, and somewhat automatically.

[dbaker]

hmm, do you think it would be worth taking a look at the BIOS settings? It has a thing called 'insyde' for controlling them. I don't know anything about it yet, but I believe it's covered in the user manual.
The fan is certainly doing its job, and I don't want the laptop to overheat, but it would be nice to make it less over-reactive :S I worry that it might wear out quicker with this constant spinning up and down.

I was taking a look at the bottom of the laptop where the air vents are last night. There's a perfectly circular one towards the left and back of the case through which I can see the fan (if it spins up and I put my hand against that vent, I can feel cold air whooshing). That also corresponds to the outlet at the side that blows out hot air. But there's another bigger, square vent on the bottom of the case (also on the left, but towards the front) which doesn't seem to have a fan behind it and feels neither hot or cold. I'm curious what that's for. I can just see a copper-colored thing through it - heatsink?
Bear in mind I've always had macs which have cleverly hidden and almost non-existent ventilation, so these things are new and fascinating to me :P

[GreyGeek]

Most CPU & GPU cooling fins and heat sinks in laptops are made of Copper. Works fairly well and is cheaper than Silver or Gold!

Thermal Conductivity, expressed in W/(cmK) @ 1 atm, 25 degrees Celsius:
silver = 4.29
copper = 4.01
gold = 3.17
aluminum = 2.37
nickel = 0.907
lead = 0.353
mercury = 0.0834

"Insyde" is UEFI software. I know absolutely nothing about UEFI BIOS settings. If your documentation doesn't mention setting hardware parameters then ...

[dbaker]

argh, I looked in the user manual and Insyde doesn't seem to let you control the fan. I guess my only option now is to contact the supplier

edit: on second thought, can GRUB help with this at all?

another edit: I've decided my initial observation about the 50C threshold isn't right. Earlier I noticed the fan spinning up when the temperature was in the low 40s, but there was a peak in CPU activity. Bizarre as this may sound, it almost looks like the fan is being controlled by CPU activity rather than temperature, although you'd expect those to go hand in hand. That's not what I'm seeing though O.o