4 ms·

Is there a timeout?

by ianbertolacci 10y ago

Is there a timeout?

vorotato 10y ago
and thus an exploit was born.
- ianbertolacci 10y ago
  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 10y ago
    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 10y ago
      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 10y ago
        You are unlikely to cause any damage, although you might make the CPU speed throttle right down
        dkersten 10y ago
        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 10y ago
      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 10y ago
        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 10y ago
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 10y ago
  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 10y ago
    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 10y ago
      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}'
sudhirj 10y ago
Siri itself has a timeout, at which point it tells you it can't hear you and goes back to sleep.

Is there a timeout?

vorotato 10y ago

and thus an exploit was born.

ianbertolacci 10y ago
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 10y ago
  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 10y ago
    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 10y ago
      You are unlikely to cause any damage, although you might make the CPU speed throttle right down
      - dkersten 10y ago
        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 10y ago
    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 10y ago
      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 10y ago

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 10y ago
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 10y ago
  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 10y ago
    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}'

sudhirj 10y ago

Siri itself has a timeout, at which point it tells you it can't hear you and goes back to sleep.