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Tell HN: MacOS turns off the fans when Siri is listening

89 points by sudhirj ↗ HN
This is something that struck me a few moments ago, because it's very logical but completely unexpected. I have a Macbook Pro that's doing some hard work with the fans on loud, and calling Siri turns the fans off the period that Siri is listening.

It's pretty amazing someone thought of that.

79 comments

[ 2.6 ms ] story [ 159 ms ] thread
ianbertolacci
Is there a timeout?
vorotato
and thus an exploit was born.
ianbertolacci
Ya, I cant imagine that they'd forget something like that. Certainly on my iPhone Siri stops listening, which should on the PC restart the fan.

I would be very entertained if you could melt chips with an overly patient Siri.

mikeash
I'd assume it wouldn't be a timeout, but a higher temperature threshold. If the machine is on the verge of melting already then you wouldn't want to turn off the fans at all.
ianbertolacci
Thats a good point, and I hope thats what they do. Im not Mac OS familiar, can other applications ask Siri to listen in? If they pause fans regardless of temperature, then it would be interesting to see if damage could be caused by an app running hot then repeatedly going to Siri.

I bet theres a way to test their cutoff mechanism. Maybe someone could run some serious bench-marking apps (maybe more CPU bound ones) and see if Siri still kills the fan at high temperatures.

Could someone potentially damage their very expensive machine to satisfy my curiosity?

jbb555
You are unlikely to cause any damage, although you might make the CPU speed throttle right down
dkersten
AFAIK most systems have an emergency shutoff anyway, so if it gets too hot, the machine simply powers off. At least, my old desktop did.
burke
If the machine is on the verge of melting already, it's likely just going to hard-shutdown below the OS level.

All this could really open them up to is a hard-shutdown, and I imagine they would have implemented this as a higher threshold, not a complete disable -- at least, it seems like a really easy problem to foresee and circumvent.

mikeash
Great point. You might make it shut off, but you should never be able to damage anything, no matter how clever the OS tries to be.
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}'
DigitalJack
I installed Intel Power Gadget. It's pretty nice actually, no options to configure but it's pretty useful information.
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

sudhirj
Siri itself has a timeout, at which point it tells you it can't hear you and goes back to sleep.
bdcrazy
My car does this when doing voice commands for radio or Phone.
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.

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.

givinguflac
Honestly it sounds like you may want to get your fans checked out. Or perhaps you work in a totally silent environment? Loud is of course subjective, but my rMBP has the quietest laptop fans I've ever used.
DigitalJack
Oh, by far this is the quietest laptop I've used. Most of the time. If I'm playing a game or docker pegs a cpu, that changes. It may still be better than other laptops, I don't know anymore, but once the fans get about 3k they start to get pretty loud. Below that I don't really hear them.
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".
thescriptkiddie
Here's my anecdote. The fans on my MacbookPro12,1 spin up to annoying levels if I even watch a YouTube video.
kstenerud
I have a 2011 model that I swapped an SSD into a few months back. I cleaned it out at that time as well. The fan's so damn noisy that the OTHER person on Skype can't hear me. The fans are on probably about 70% of the time I'm using the machine, and often I have to just start shutting down programs at random when I'm done until the fan stops, or else it will run like that for hours. Activity Monitor is particularly bad for CPU usage.
cordite
My fan rarely turns on, and it is barely audible.

It seems the tolerance is far beyond leg-scalding for my MBP, though it only gets to that point when recompiling a bunch of version specific libraries in a sandbox for over 10 minutes.

hmottestad
My work paid for the 2.8 ghz upgrade on my macbook pro 15". When doing video chat in chrome it scales up one of the cores to max and heats up quickly making the fans run at max after 10-15 min.

My older macbook pro 15" with the stock CPU doesn't get as hot and the fans run much less on that one.

haikuginger
Google Hangouts is an awful resource hog.
nthj
FWIW, I (ironically?) have a lot more success running Hangouts on Safari than I do Chrome, on both a 2013 11" Air and a 13" i7 MBP.
coldtea
I have an MBPr and do frequent 1080p/4k renders that utilize all 4 cores to max, and I can barely hear the fans...
givinguflac
Seriously. I use SMCfancontrol to run the fans at max most of the time, and I can't tell they're even running unless the room is very quiet. The new fans in the rMBP's are great.
jxy
Does it stop the CPU hungry process too?
carlosfvp
Good point, otherwise the hardware might damage with constant usage of Siri, or is this the actual plan of Apple?
n1000
Whenever the CPU gets too hot the Macbooks throttle. So I would say so.
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.

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.

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

throwanem
Can it really be called "lock-in" when it's an effect of changes which to many people make the product more desirable for its own sake? Microsoft in the 90s wasn't really known for such behavior, to say the very least.
AstralStorm
The alternate, Aldous Huxley version of lock-in, instead of the George Orwell version of lock-in.
throwanem
Do you think it's possible that such comparisons grow dull with overuse?
tedunangst
How dare a company make a product people like!
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

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.
justinhj
They leave that choice to the user since you can disable the content of sms appearing on the lock screen. Not that I think that it's a good idea to leave security decisions like that to users
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
joshmanders
Sending and receiving non-iOS/iMessage texts require your phone to be near your computer. I don't believe any company sends 2FA codes to you through iMessage.
networked
Google's is a more convenient general-case solution, but Deutsche Bank may actually want to trick the user into reading the sum and the purpose of the transaction before he or she gets to the code. It could prevent a race condition type of attack if the user's PC is compromised.
tedmiston
I don't think of it like that on OS X (err macOS), but rather, they're making the most poweruser features non-defaults. All of the friendlier features can be disabled though; I can't think of any functionality that's been totally removed.
tammer
I used to think this way. I remember writing an angry rant comment on a review of the Magic Trackpad, saying it was the beginning of the end for precise, professional input.

Now, of course, I exclusively use the MT with my Macs & plan on moving to iPad Pro. I've realized that what actually makes someone more efficient and productive are not the tools that seem the most complex or offer the most options. What I've realized is that the biggest impediment to productive general computing is what I'm going to coin as "context exhaustion."

iOS is an OS designed to be orders of magnitude better in this category than a PC OS. A roll-your-own, completely open Linux distro is the opposite. At the end of the day, the tool that requires the least maintenance and repetition of movements is the tool that actually offers the most real productivity advancement. To use my example, once I realized giving up precise input was completely negated by the freedom of zoom gestures, I realized the great economic benefit of the MT. I'm critically faster at navigating interfaces with gestures like double-tap-to-zoom.

The best part is, Apple isn't trying to achieve market dominance the way MS did. They're simply offering high end products in high demand - and if they don't match your vision of what productive work should look like, you'll always have other options that will be much more popular in terms of market share.

A lot of focused complaints like these, I think, are the result of Apple fans not taking advantage of new features that reduce contexts.

joshmanders
Well put. Exactly how I feel. So many people are like "Yeah, enjoy your non-customizable iPhone." or other similar stuff about OS X/macOS but those are the beauties to me. The reasons I enjoy it so much. I don't want to spend 45 minutes customizing my devices. I just want to use them. I don't even care about the wallpaper on my machine anymore. I have an app installed that randomly updates the wallpaper using unsplash.com photos just incase there's that off chance that I see my desktop.

Some people like to be productive, others like to control every aspect of their devices. It's okay. Choose based on your needs.

n1000
I can't say I haven't tried. Every 12 months or so I install Linux and so far always came back. I bought a Surface Pro 4 because it seemed so Appleish, only I hardly ever use it. Windows 10 seems like the worst of both worlds. I spent hours on hacking simple configurations (as in *nix) and feel under heavier surveillance than on OS X.
ninedays
The problem with this reasoning is that you assumed that Apple always had lots of money and that Apple always stockpile billions of cash but that is completely untrue. Back when Apple was months away from bankruptcy, Apple still had this dedication to details that we still find amazing today.

I am amazed by how quickly people forgot in what position Apple was more than a decade ago.

Apple caring about their products has nothing to with money. It just shows that they really care.

505
"caring about their products has nothing to with money. It just shows that they really care."

I almost completely agree. But IMHO "really care" includes Apple organising its business so that really caring ends up making them money, without its being zero-sum.

behnamoh
You have to understand, Apple's strategy is and has always been to make extraordinary products without shouting about it. Sure, they do advertise and run conferences, but they never bold these little details. This explains why caring about products is something all Apple employees do without thinking about monetizing it. It's true what they say: Steve Jobs' DNA still runs through Apple.

Microsoft also has billions of cash, but never have they done such a thing. They even had more time and money than Apple in the 90s.

moepstar
Should be in there since 10.9.x, albeit in the form of the dictation feature, not Siri...
jsonau
Would noise cancelling(ANC) help in this case, even if the mic and fan are near each other?
AstralStorm
Yes, a lot. This is a simple case for a noise canceller. Stationary known wideband source of noise.
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.
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.
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.
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.