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visionOS thermally throttles based on how much it hears the fans in the mics

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Re: visionOS thermally throttles based on how much it hears the fans in the mics

#41

Post by makeitdouble »

bitwize wrote: post #40
jfoster wrote: post #10

Earlier quoted context omitted.

It seems a mis-prioritization of the kind that makes me dislike Apple products. To avoid the imperfection of a bit of fan noise, throttle the entire experience. Great.

Fine, their products are not made for you. But they're a trillion dollar company because of their relentless focus on the end-user experience which you happen to dislike, but which most people love.

NVidia passed them in valuation, what does that say about NVidia's end-user experience ?

Profits or valuation can't be a measure of whether a company is doing right to their users or their UX quality.

Re: visionOS thermally throttles based on how much it hears the fans in the mics

#42

Post by mlyle »

immibis wrote: post #28
thebruce87m wrote: post #23

Earlier quoted context omitted.

They do the same with clock signals in some systems. Similar idea to avoid high peaks at a single frequency: > Spread spectrum clocking is a technique used in electronics design to intentionally modulate the ideal position of the clock edge such that the resulting signal’s spectrum is “spread”, around the ideal frequency of the clock. In timing circuits, this has the advantage of reducing Electromagnetic Interference…

This is controversial, because the same amount of noise is emitted, just with a different shape that is still able to be picked up by radio receivers just as well, but is more likely to pass regulatory tests.

We have a standard for the maximum energy on given frequencies, not the total EM emitted. Spread spectrum clocking definitely reduces the peak energy on specific frequencies, which is usually what you care about more.

I guess it makes you more likely to experience interference, but the interference you'll experience, on average, will be much less severe.

Re: visionOS thermally throttles based on how much it hears the fans in the mics

#43

Post by bitwize »

makeitdouble wrote: post #41
bitwize wrote: post #40

Earlier quoted context omitted.

Fine, their products are not made for you. But they're a trillion dollar company because of their relentless focus on the end-user experience which you happen to dislike, but which most people love.

NVidia passed them in valuation, what does that say about NVidia's end-user experience ? Profits or valuation can't be a measure of whether a company is doing right to their users or their UX quality.

UX isn't NVIDIA's business model. It is Apple's, and they've found there's shittons of money to be made giving a shit about UX, especially when virtually no one else will.

Re: visionOS thermally throttles based on how much it hears the fans in the mics

#44

Post by immibis »

mlyle wrote: post #42
immibis wrote: post #28

Earlier quoted context omitted.

This is controversial, because the same amount of noise is emitted, just with a different shape that is still able to be picked up by radio receivers just as well, but is more likely to pass regulatory tests.

We have a standard for the maximum energy on given frequencies, not the total EM emitted. Spread spectrum clocking definitely reduces the peak energy on specific frequencies, which is usually what you care about more. I guess it makes you more likely to experience interference, but the interference you'll experience, on average, will be much less severe.

No radio receives exactly a single frequency. They all receive a range.

Re: visionOS thermally throttles based on how much it hears the fans in the mics

#45

Post by jayd16 »

tliltocatl wrote: post #36
dvh wrote: post #14

Another trick is not to use constant RPM because you can hit some mechanical resonance point, but constantly varying RPM around target RPM so that the system even if it hits resonance stays there only for a brief moment and won't start vibrating.

Offtopic: constantly varying RPM across a resonance point might not be a good idea, it was exactly what blew up Sayano-Shushenskaya Dam.

I that worse than accidentally landing on it?

Re: visionOS thermally throttles based on how much it hears the fans in the mics

#46

Post by jayd16 »

raverbashing wrote: post #20

For those who are confused: the title is a bit misleading, it's actually the other way people might expect (if you read the thread) Noisy environment: turn the fans all the way as the user -> more cooling -> processor doesn't throttle Quiet environment: turn the fans down -> processor throttles

For VR perf its probably a bad idea to throttle the performance. A better goal would be to balance user comfort. You can trade noise for thermal comfort.

Re: visionOS thermally throttles based on how much it hears the fans in the mics

#47

Post by mlyle »

immibis wrote: post #44
mlyle wrote: post #42

Earlier quoted context omitted.

We have a standard for the maximum energy on given frequencies, not the total EM emitted. Spread spectrum clocking definitely reduces the peak energy on specific frequencies, which is usually what you care about more. I guess it makes you more likely to experience interference, but the interference you'll experience, on average, will be much less severe.

No radio receives exactly a single frequency. They all receive a range.

Sure--- I'm familiar with the bandwidth theorem. In general, a single narrow carrier with lots of energy inside your channel is more harmful to demodulators than spreading the interference over 20MHz, most of which isn't even on top of your channel (or, if your channels are reaaaaaallly wide, it's still just a slightly increased noise floor instead of a strong single frequency swamping your signal).

I've designed a lot of radio systems, built a lot of demodulators, and calculated a lot of link budgets. It's best to assume that people know a fair bit, here, instead of tossing out the simplistic dismissal.

I'm also an amateur radio operator, and I know that strong carriers are often far worse for me down in HF than the same energy spread out over tens of thousands of cycles; though I can often notch carriers, I only have so much dynamic range.

Re: visionOS thermally throttles based on how much it hears the fans in the mics

#48

Post by whyoh »

FireBeyond wrote: post #38
whyoh wrote: post #32

Earlier quoted context omitted.

Because the RPM of a fan is not a 100% reliable indicator of its loudness. Sometimes a lower speed can even be louder than a higher one, because of certain resonances...

Presumably, knowing the fan you've installed into the device you've designed, you could map those noisy areas...

Yes, that could work (it would need to be done for each fan individually, because of manufacturing variation). But it's still not guaranteed that the fan will keep working the same way in the future, after some use/deterioration or in untested conditions.

Re: visionOS thermally throttles based on how much it hears the fans in the mics

#49

Post by makeitdouble »

bitwize wrote: post #43
makeitdouble wrote: post #41

Earlier quoted context omitted.

NVidia passed them in valuation, what does that say about NVidia's end-user experience ? Profits or valuation can't be a measure of whether a company is doing right to their users or their UX quality.

UX isn't NVIDIA's business model. It is Apple's, and they've found there's shittons of money to be made giving a shit about UX, especially when virtually no one else will.

Apple's current position is cemented by ARM chip performance.

I maintain, bringing market cap to explain whether a company is good at or cares about UX is just irrelevant.

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