Fan+heat troubles on MacBook Pro

[Steven Noonan]

On Mon, Nov 29, 2010 at 3:09 AM, christoffer.buchholz at gmail.com
<christoffer.buchholz at gmail.com> wrote:
> Ah okay, I see. As I mentioned, I am not very skilled in this department.
>
> About the fan. Right now, one sensor is recording +70.5°C and another one is
> recording +69.0°C. The rest of the sensors records temperatures around
> +40.0°C. The fan is running at only 2001 RPM, and I don't see it move up and
> down in speed ever. Modules coretemp and applesmc is loaded. I see that
> changing the minimum speed would prevent heat, but on the other hand, making
> it go 4000 RPM at the minimum, it would make quite a noisy laptop. I see
> this could be a temporary solution, but not good in the long run.
>
> You don't have any clue to why the fan is not behaving correctly and just
> stays just around the minimum speed, instead of actually keeping the system
> cooled down?

No, I don't know what the cause could be. Perhaps the people who
developed the applesmc driver would know. I've added Henrik, the
current maintainer of applesmc, to the CC list. Henrik, any idea why
the fans wouldn't spin up when the temperature increases so much?
Could applesmc have something to do with this?

Chris, you could try to test and see if applesmc is the cause. Try
preventing applesmc from loading (add 'blacklist applesmc' to
/etc/modprobe.d/blacklist.conf), and see if your fans still stay at
2000 RPM under CPU-heavy workloads. Of course, you'll have to just
listen to find out if the fans spin up instead of checking sysfs, but
this will at least help debug the situation.

>
> And thank you for your help so far.
>
> On Mon, Nov 29, 2010 at 11:48 AM, Steven Noonan <steven at uplinklabs.net>
> wrote:
>>
>> On Mon, Nov 29, 2010 at 2:18 AM, christoffer.buchholz at gmail.com
>> <christoffer.buchholz at gmail.com> wrote:
>> > Thank you for your quick reply!
>> > To answer you questions...
>> >
>> > 1) uname -a reads "Linux gomet 2.6.35.6-48.fc14.x86_64" - I have also
>> > tried
>> > with the kernel from the bleeding edge fedora 15 repo, but that didnt
>> > change
>> > much if anything at all.
>>
>> Alright, so the stock Fedora kernel, then.
>>
>> > 2) According to apple documentation, my processor is a "2.53GHz Intel
>> > Core 2
>> > Duo processor with 3MB on-chip shared L2 cache running 1:1 with
>> > processor
>> > speed" and has a "1066MHz frontside bus" <- I guess that is the rated
>> > clock
>> > frequency.
>>
>> 2.53 GHz is the rated clock frequency. :)
>>
>> > 3) 'cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor' reads
>> > "ondemand"
>>
>> Good, so it should be scaling...
>>
>> > 4) 'cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq' reads
>> > "798000" and it does that even when i shut down all apps running, so it
>> > seems its actually not so ondemand
>>
>> And it is scaling down properly. 798MHz is as low as SpeedStep allows
>> that processor to go.
>>
>> > 5) I'm not very technical, so but here's some of the stuff, which I
>> > guess is
>> > the important part, from powertop. It doesnt really change more than a
>> > few
>> > numbers up and down, so it should be good: http://fpaste.org/7G9b/
>>
>> Looks like it's staying clocked down to 798MHz just fine, so there's
>> no way that cpufreq is screwing up.
>>
>> > 6) The output from /proc/interrupts doesnt seem to change that much. You
>> > can
>> > see the output from '/proc/interrupts; sleep 0.5s; cat /proc/interrupts'
>> > here http://fpaste.org/QXVO/
>>
>> Okay, it looks like interrupts are being handled properly. Nothing
>> there jumps out as abnormal.
>>
>> Rereading your original post, I think I was an idiot and missed
>> something that I shouldn't have... You mention that the "fan is not
>> functioning properly". Is this a hardware thing you're trying to work
>> around, or are the fans just not spinning up when the machine gets
>> warm? If you don't mind a performance impact, you could change the
>> scaling governor to 'powersave', and the CPU won't automatically clock
>> up under load. Alternatively, you could probably set the minimum fan
>> speeds to a higher level (they're probably at 2000 RPM by default, so
>> you may want to try 4000). Do this:
>>
>> ls /sys/devices/platform/applesmc.*/fan*_min
>>
>> It will probably list a couple different fans there, and you can 'cat'
>> them to see what the minimum is currently set to, or you can do
>> something like:
>>
>> echo 4000 > /sys/devices/platform/applesmc.X/fanY_min
>>
>> (obviously, replacing X and Y in the above with whatever the actual
>> values are from the above 'ls' output)
>>
>> I haven't looked at my mid 2010 MacBook Pro's applesmc folder, but on
>> my 2007 MacBook Pro, there are fan1_min and fan2_min. They can be set
>> independently, so if you want one at 2000RPM and the other at 6000RPM,
>> there's nothing to prevent you from doing so. You probably will want
>> them to both be at the same speed, though.
>
>