
Tell HN: MacOS turns off the fans when Siri is listening - sudhirj
This is something that struck me a few moments ago, because it&#x27;s very logical but completely unexpected. I have a Macbook Pro that&#x27;s doing some hard work with the fans on loud, and calling Siri turns the fans off the period that Siri is listening.<p>It&#x27;s pretty amazing someone thought of that.
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n1000
It's been around for a while already. The dictation feature in OS X 10.10
already knows that trick. The thought of the little thinks is what still makes
me stick with OS X.

~~~
hashkb
> The thought of the little [things] is what still makes me stick with OS X.

This rubs me the wrong way because it's a vicious (positive, I guess) cycle.
You keep buying iPhones, they stockpile billions in cash, and they can "think
of the little things" (which is really just "How can we make OS X more like
iOS and less suitable for power users?").

It's sad... but I can't imagine anyone taking the time to hack this together
on their *nix laptop, and even if they did, it's not likely to be portable
until a handful of other tinkerers donate their time. This will bring the
downvotes, but the way we're stuck on Apple these days is far worse than the
MS lock-in we revolted about in the 90s.

~~~
matt4077
I don't think it's about the money, it's more of a matter of capability and
simply "caring". Regarding the latter: it seems that Apple has managed to
build an organization where everyone knows that details matter and everyone
identifies with their work.

Here's a wonderful example: two SMS, one from google and one from Deutsche
Bank (who, at the time, probably had enough money to care about details)
[https://twitter.com/salzprojekt/status/707303168703602688](https://twitter.com/salzprojekt/status/707303168703602688)

Both SMS have the same purpose: sending me a single-use login token. But only
google thought enough about it to change the sentence structure so as to make
the code visible without unlocking the phone.

~~~
hirsin
Is the point of 2FA to show you have possession of another device, or access
to another device? While I'm in the same boat and appreciate seeing the code
above the fold, for really secure things I'd prefer the Deutsche Bank example.

~~~
calbear81
I noticed that since I have iMessage synced to my Macbook, if I ever lost my
laptop and someone tried to hack my accounts, they would get the 2FA access
code on the laptop they stole.

~~~
redler
Those codes come across as actual SMS messages to the associated phone number.
It appears on your laptop only when the phone is near enough to it that the
"continuity" feature is engaged. You should be safe from this threat as long
as the laptop isn't lost very nearby.

~~~
ephimetheus
That is not true. SMS messages arrive as long as the phone is online,
regardless of location.

~~~
redler
I've never seen this behavior with my own devices, and cursory searching turns
up similar results. Certainly I could be wrong, so can you point me to any
references that describe the "proximity not required" behavior?

~~~
ephimetheus
Well no. I had my iPad on a trip and left my phone at home plugged into the
wall. Could send and receive text messages without problems

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kstenerud
They have to. Any time my MBP is working really hard, say, compiling, or
talking on skype, or watching a video, or loading a web page, or browsing the
filesystem, the fan ramps up like a turbine. It gets so bad that the
microphone can't accurately pick up my voice.

~~~
alexbock
Are you using an older model that hasn't been cleaned in a while? I use an
early 2013 15" MBP and the only time I ever hear the fans is when I'm doing
compilation with 8 threads (100% CPU usage on all four cores).

~~~
DigitalJack
I've got a 2015 15" mbpr, and it doesn't take much for the fans to reach noisy
speeds. one core pegged will do it after a few seconds. I run into this a lot
with the new docker daemon.

edit: just timed it (yes > /dev/null), it takes about 60 seconds of one core
pegged to ramp up the fan to audible. And I'm used to silent so audible is
noisy to me.

Two cores pegged gets loud.

~~~
jrowley
I'll echo you that my 2015 15" mbpr really screams the majority of the time. I
probably should do a fresh install with the latest OS but moving files around
is such a pain.

Maybe we are in quiet environments and notice them more than other people?

~~~
hedgehog
If there's an app causing it then the "Energy" tab in Activity Monitor should
show you which one. Google and Adobe apps along with their helper services are
particularly poorly behaved even when "idle".

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crymer11
And only if you're using the internal microphone. I was trying to test this
and couldn't reproduce it until I realized I was using headphones with a mic.
Unplugged the headphones, activated Siri and the fan instantly turned off.

~~~
AstralStorm
I wonder how they prevent their CPUs from burning up when they do this and
there happens to be some kind of heavy load in the background...

Is someone up for a free warranty Macbook replacement? ;)

~~~
jlawer
The intel CPUs have pretty good thermal management. I suspect what will happen
is the CPU will just start throttling itself to cool down if you kept making
the OS spin down the fans.

Even back in the P4 days there were videos of people ripping Heat sinks off
intel chips while running and the system throttling down and speeding back up
as the heat sink is replaced.

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stuaxo
They probably thought of it because they were getting unexpectedly bad results
using the internal microphone.

I guess it ramps the priority of everything else down as well.

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fractal618
So, can I overheat my friends laptop, by saying "Siri" and proceeding to read
war and peace?

~~~
wingerlang
If they thought about turning it off to increase the clarity of the speech,
they probably thought of turning them on in case the computer is about to
explode.

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DiabloD3
My MBPr 13" (Late 2012) turns off the left fan and left speaker when the
microphone (which is on the left side) is in use.

This is entirely in software, and Windows 10 does not also do the same. OSX
has done this since 10.8, which came with the MBPr.

~~~
Unklejoe
I guess Windows is at a disadvantage here since it doesn't know the physical
layout of the components on the hardware it's running on. It would be up to
the laptop manufacturers to include a driver to do such.

~~~
LeifCarrotson
> It would be up to the laptop manufacturers to include a driver to do such.

Which means it's not going to happen, and if it does, it's not going to work
right.

The "IBM Compatible" or "Wintel" commodity hardware platform has proven to be
a powerful force for making computers less expensive and easier to use, but
there's something to be said for vertical integration.

~~~
yuhong
I once wondered what would happen if Intel bought Compaq in 1991, and
eventually AMD does something similar in the early 2000s (it was in 2006 that
they bought ATI for example). It would not quite be vertical integration, but
the point is that it would be still a step forward.

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jxy
Does it stop the CPU hungry process too?

~~~
jxy
Why the down votes? Isn't it important? If I'm running some CPU intensive
processes, I would hope it could send a SIGSTOP to the process so it wouldn't
burn itself.

Throttling CPU frequency would help, but I expect siri needs some CPU too.

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ianbertolacci
Is there a timeout?

~~~
DigitalJack
yes. I've got 3 cores pegged now, fan shuts off for a few seconds and if I
don't say anything it bails and the fans come back.

just takes about 10 seconds.

edit: I was able to keep activating siri and have the fans off while 4 cores
pegged for quite a while. I don't know if CPU throttling kicked in or not, not
sure how to check.

~~~
ianbertolacci
We were also wondering about existing temperature conditions. For example, I
might be running some super benchmark that pegs the core temperature high.
What happens when Siri turns on? If it still shuts down the fan thats bad. I
could potentially keep prompting Siri (to turn off the fan) and drive the
temperature a bit higher.

~~~
DigitalJack
I don't have an app for monitoring cpu temps right now, and don't know if
there is a CLI way to do it.

I was able to keep the fan off for probably a minute before I stopped. I am
interested to find out if intel's cpu throttling kicked in.

edit: installed Intel Power Gadget.

with 4 cores pegged (4 actual cores), the CPU was turbo-boosted (3.0GHz on my
laptop). As I prevented the fans from running via Siri, the cpu throttled back
to normal rated speed. Temperature varied by a few degrees C hovering around
99C. I did this for approximately a minute or so.

It didn't go below the rated speed (2.5GHz on my laptop).

edit2: I did it again with 4 cores pegged and 4 HT cores pegged. It didn't
throttle below 2.5, but I did see that the "yes" processes were throttled
back. when I glanced before stopping, they were all at 80% instead of 95+%

~~~
burke
There's no default utility for this. There's some sysctl values for the CPU
and the GPU but they don't actually give you a temperature.

There's an API for this in IOKit. Easiest way I've found to get at it on the
CLI is:

    
    
        gem install istats
        istats cpu temp | awk '{gsub(/[^0-9\.]/,"",$3);print $3}'

~~~
grkvlt
Just FYI, I had to do the following:

    
    
        $ gem install istats
        ERROR:  Could not find a valid gem 'istats' (>= 0) in any repository
        ERROR:  Possible alternatives: iStats
        $ gem install iStats
        Fetching: sparkr-0.4.1.gem (100%)
        ERROR:  While executing gem ... (Gem::FilePermissionError)
            You don't have write permissions for the /Library/Ruby/Gems/2.0.0 directory.
        $ sudo gem install iStats
        Fetching: sparkr-0.4.1.gem (100%)
        Successfully installed sparkr-0.4.1
        [...]
        This could take a while...
    

Then, I discovered it uses sparklines for output:

    
    
        $ istats cpu
        CPU temp: 60.625°C  
    

Which is pretty cool.

 _EDIT: the sparkline doesn 't show here, but it's a little bar-chart
histogram_

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nikolay
It's kinda stupid - instead of intelligently filtering the noise (it knows the
acoustics, the RPM of the fan, etc).

~~~
sclangdon
Since when were simple solutions considered stupid? If filtering audio (which
will probably only work the CPU, and thus the fan, more) is smarter than
stopping a fan, I must be as dumb as bricks.

~~~
nikolay
It's a simple non-solution as noise is not coming only from the fan. Yes,
you're reducing one that's easy to eliminate, but the problem still exists.

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mnovaes
Hopefully not for long enough to fry your circuitry. :)

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jsonau
Would noise cancelling(ANC) help in this case, even if the mic and fan are
near each other?

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AstralStorm
Yes, a lot. This is a simple case for a noise canceller. Stationary known
wideband source of noise.

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p333347
Never used a Mac but this seems more like a workaround for the noise filtering
problem.

~~~
nom
Yes agreed, it really sounds like a workaround. They improve the detection
rate by reducing the noise floor. I find it interesting that they took the
time to implement it, it must have cost a considerable amount of work that
they could have put into filter algorithms instead. Fan noise sounds like an
artifact that is easy to filter, but I'm probably wrong.

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bdcrazy
My car does this when doing voice commands for radio or Phone.

