Why is sound seemingly faster than photons with computers?

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Mootoo
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18 Aug 2016, 10:06 am

I'm not sure this is the average anecdote, or perhaps it is - still just my own experience - but whenever an application freezes sound is the first to come back into existence, which is annoying if the picture is still frozen... so, why does it seemingly contradict the speed of sound and light?



Last edited by Mootoo on 18 Aug 2016, 10:21 am, edited 1 time in total.

BaalChatzaf
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18 Aug 2016, 10:16 am

Mootoo wrote:
I'm not sure this is the average anecdote, or perhaps it is - still just my own experience - but whenever an application freezes sound is the first to come back into existence, which is annoying if the picture is still frozen... so, why does it seemingly contract the speed of sound and light?


It is photons that turn your computer sound on/off.


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Nine7752
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18 Aug 2016, 10:42 am

This is because of the audio and graphics drivers in your system. They operate differently in a crash, and maybe sound keeps going longer (dumping its buffer or something) than video.

It doesn't have to do with the speed of the sound or light coming from your machine, that's so small it wouldn't make a difference anyway, unless your computer were a mile away from you.


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naturalplastic
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19 Aug 2016, 6:05 am

What Nine said.

A movie (even a silent movie) takes more memory than does a record album of music. So you would expect video to be more unwieldy than audio, and for it crash sooner, and to take longer to recover from a crash than audio.

Frankly your question is kinda silly: if your theory were right (that sound really moves faster than light, and that the short distance between you and your desk top were enough to show the time lag between the two) then the humans around you in your real life would appear to speak with their lips out of sync with their voices.

You would hear your spouse's voice first, and THEN see your spouse's lips move, as if you were living in a badly edited movie! Lol!



Aristophanes
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19 Aug 2016, 8:07 am

It's your OS or possibly bios/uefi. When the computer is started, or the OS recovers from a malfunction and "resets" itself without booting, it generally goes through a checklist to make sure the hardware is attached and receiving/sending data (I refrain from using "working properly" because the check doesn't really do that, just makes sure there's crap there and it's sending and receiving data-- doesn't mean the data is not corrupt). Your software merely tests the sound card before the video card-- to be honest it's probably already checked every other component of your system (pci controller, usb hubs, drives, etc) before it even got to video and sound.

So no, computers don't break physics, it's merely a programming "fielder's choice".



saxgeek
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28 Aug 2016, 11:54 am

I've never experienced the issue you're talking about. However, when I watch YouTube videos on a slow computer, the video will often get choppy and lag behind the audio. Most of the time, it takes a lot more processing power to decode video than it does audio. This is a software problem. It has nothing to do with the speed of sound and light.



BTDT
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28 Aug 2016, 11:57 am

Audio has a much slower data rate than video. It doesn't take long to get enough data to restart audio versus what you need for video.



Tiankay
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28 Aug 2016, 2:30 pm

Baiscly it has nothing to do with photons. A Computer has different components to run specific tasks. Very plain basic these are the main ones -

CPU = Central Processing Unit
RAM = Random Access Memory
GPU = Graphics Processing Unit (Wich has its own set of RAM, called Video-RAM or VRAM)
SPU = Sound Processing Unit (or just Soundcard or Soundchip)
NIC = Network Interface Card
Also needed is a permanent data storage, but that doesnt matter for this Example.

The CPU runs and coordinates most of the tasks a PC can do. Therefore it has the RAM as working memory. Dont get confused with the random here, it means that it can be accessed at any random point in time at any data location. When you run a multimedia task, lets say streaming a video. It uses the NIC to retrive the data from your internet connection (probably a router) and then seperates the data and sends it to the different components to do their job. Usually multimedia data is compressed, so it needs to be decompressed before it can be played to you. This is done live, but data size for audio is much smaller then it is for video and it gets processed differently. The video signal gets sent to the GPU as it is, the audio gets decompressed by the CPU and then sent to the SPU to process it into a analog signal. The GPU does the video decompression all by itself, but it needs to be coordinated from the CPU.

Now when your PC freezes the GPU cannot render any new video because the CPU isnt telling it what to do anymore. The SPU is much more primitive then a GPU and basicly just processes any data it gets fed, when it gets fed. While a GPU needs to be told what to do from the CPU constantly. So when the application (partially) "de-freezes" the CPU starts decompressing the audio again and feeds it to the SPU. That takes minimal computing power to do and as the SPU just works when it gets fed, cracking audio will occur when it doesnt get a constant data stream from the CPU. The GPU on the other side needs a constant data stream for decompression and rendering of the image or it will either show a black screen or the last rendered image until it gets more data and some orders from the CPU to work with.

Now this example was about video streaming and it is very simplified, but it applies to any freeze where this behavior occurs. The CPU is unable to feed constant data to both the GPU and the SPU, but because the SPU is alot less complex than a GPU it just works with that chopped off data stream while the GPU is unable to do so. Even when working on your desktop...

There can be multiple reasons for it, common ones are
Trying to run new power-hungry software on very old hardware, thus overloading your components.
Faulty drivers
Bugs (Errors in the software)
Running many power-hungry tasks at once, again overloading your components
Having another program running at very high CPU priority
Viruses
and probably more, but i cant think of them now...

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mr_bigmouth_502
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28 Aug 2016, 2:38 pm

It's nothing to do with physics; your computer is probably giving higher priority to your audio drivers than your sound drivers. Blame programming.


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naturalplastic
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28 Aug 2016, 3:29 pm

mr_bigmouth_502 wrote:
It's nothing to do with physics; your computer is probably giving higher priority to your audio drivers than your sound drivers. Blame programming.


You musta meant "video drivers than your sound drivers" , and not "...audio than sound...." because "audio" and "sound" are the same thing.



mr_bigmouth_502
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29 Aug 2016, 2:27 am

naturalplastic wrote:
mr_bigmouth_502 wrote:
It's nothing to do with physics; your computer is probably giving higher priority to your audio drivers than your sound drivers. Blame programming.


You musta meant "video drivers than your sound drivers" , and not "...audio than sound...." because "audio" and "sound" are the same thing.

I meant "audio than video". :P I had a brain fart.


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