# Getting CPU fans to run to cool laptop

## diepchess

hi!

Noticed the CPU fans are not or hardly running at the macbookpro 3.1 i've got.

Managed to install lm_sensors.

It gives me:

coretemp-iso-0000

Adapter: ISA adapter

Core 0:     +42C   (high= +100.0 C, crit = +100.0C)

Core 1:     +43C   (high= +100.0 C, crit = +100.0C)

I'm not seeing the fan readings with lm_sensors. How to fix that?

That +100C is of course gonna kill the laptop.

Want to modify that for example to 35C to hear the fans run and to

a higher value (say 60C) in case it works.

Note I"m blowing with external fan air towards laptop and it sits at copper heatsinks.

Possibly linux is not steering the fans at all (if they would run real low rpm, i would not be able to hear them anyway).

So 40-43C right now for idle laptop is very high temperature. 

Without the huge fan behind it, it would get real hot the laptop (happened yesterday).

How do i see the RPMs of the fans and how do i get them moving?

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## krinn

 *diepchess wrote:*   

> So 40-43C right now for idle laptop is very high temperature.

 

No it's 40-43C for idle cpu, and that's not shocking values for a cpu.

And the coretemp gave you the core temperature, the inner temp of the core, when you read crit = 100°C read that more like at 100°C you're reaching critical temp for your cpu ; look at the diff for my CPU temp and core temp

This will drive you to your next question

How do you read your laptop/case temp ?

Well, if you case/laptop have one, you could get it from lmsensors as well, and configuring lmsensors could be seen there : https://wiki.gentoo.org/wiki/Lm_sensors

Here's my output, yes, no chassis info for me, but i'm not using a laptop

```
atk0110-acpi-0

Adapter: ACPI interface

Vcore Voltage:       +0.95 V  (min =  +0.80 V, max =  +1.60 V)

 +3.3 Voltage:       +3.33 V  (min =  +2.97 V, max =  +3.63 V)

 +5 Voltage:         +5.21 V  (min =  +4.50 V, max =  +5.50 V)

 +12 Voltage:       +12.03 V  (min = +10.20 V, max = +13.80 V)

CPU FAN Speed:      1259 RPM  (min =  600 RPM, max = 7200 RPM)

CHASSIS1 FAN Speed:    0 RPM  (min =  600 RPM, max = 7200 RPM)

CHASSIS2 FAN Speed:    0 RPM  (min =  600 RPM, max = 7200 RPM)

POWER FAN Speed:       0 RPM  (min =    0 RPM, max = 7200 RPM)

CPU Temperature:     +36.5°C  (high = +60.0°C, crit = +75.0°C)

MB Temperature:      +44.0°C  (high = +45.0°C, crit = +75.0°C)

coretemp-isa-0000

Adapter: ISA adapter

Core 0:       +44.0°C  (high = +80.0°C, crit = +100.0°C)

Core 1:       +43.0°C  (high = +80.0°C, crit = +100.0°C)

Core 2:       +43.0°C  (high = +80.0°C, crit = +100.0°C)

Core 3:       +44.0°C  (high = +80.0°C, crit = +100.0°C)

```

But you might as well be lucky as with a mark/model you can make specific search in forum/google for a top answer.

edit to add: i suppose MB temp should be near close to chassis/laptop temp if that could help you, but some M/B have also cooling device.

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## diepchess

I'm using lmsensors indeed. 

Lmsensors gives the output as i wrote it down.

It's true that 40C in itself wouldnt be shocking yet the fact that the laptop will overheat if i turn off the 17CM fan is pretty bad  :Smile: 

It's 58C now and laptop is idle meanwhile a fan blows outside of laptop. that fan is 17CM and it blows 100CFM towards laptop.

Underneath laptop there is copper from a bunch of heatsinks i put there upside down. Those heatsinks get hot. 

Those heatsinks get cooled obviously also by the 100CFM that blows there.

That is what keeps the laptop not overheating.

If i turn off the 17CM fan then the temperature rises easily to 100C.

it's a macbookpro 3.1 and it has 2 internal fans. 

If those run with laptop completely idle the laptop should be pretty cool  :Smile: 

So i'm trying to find a way to activate the 2 internal fans. 

The modules i2c-dev and coretemp currently are loaded for that purpose.

What other module would i need to activate the 2 internal fans so that with speedfan i can set their speeds?

Thanks,

Vincent

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## diepchess

Note i found this here: https://github.com/dgraziotin/Fan-Control-Daemon

"It requires coretemp and applesmc kernel modules to be loaded."

Yet when i do a search for applesmc:

emerge --search applesmc

It's not there. Let's google more  :Smile: 

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## diepchess

Oh that took me a while - hadn't realized applesmc is also a kernel module  :Smile: 

Let's see whether it works ok now - hope so  :Smile: 

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## diepchess

GREAT - this problem has been solved as it seems. I can see the RPM of the 2 fans now!

So i assume i'll manage to control them as well now!

This is progress - now important is to get the graphics card going on this laptop. Let's hope Nvidia helps a tad more with that  :Smile: 

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