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Why does a Music Server require high processing CPU power?

I noticed that some music servers use, for example, a dual multicore CPU’s running under a custom assembled operating system.  In addition, the server is powered by a linear power supply with choke regulation and a large capacitor bank utilizing the highest audiophile grade capacitors.  Various other music servers have similar high CPU processing capabilities.  

I know that music is played in real-time so there is not much time to do any large amounts of processing.  I also know that the data stream needs to free of jitter and all other forms of extra noise and distortion.   I believe that inputs and outputs are happening at the same time (I think).

I also know that Music Servers needs to support File Formats of FLAC, ALAC, WAV, AIFF, MP3, AAC, OGG, WMA, WMA-L, DSF, DFF, Native Sampling Rates of 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz, 352.8kHz, 384kHz, 705.6kHz, and 768kHz and DSD formats of DSD64, DSD128, DSD256 and DSD512 including Bit Depths of 16 and 24.  

Why does a music server require high processing power?   Does the list above of supported formats etc. require high processing power?  Assuming the Music Server is not a DAC, or a pre-amp, what is going on that requires this much processing power?   

What processing is going on in a music server?  How much processing power does a music server require?  

Am I missing something?   Thanks.   


hgeifman
hgeifman OP
2,256 posts
 
@lalitk, Sorry, I do not understand and need more clarification.
  
Let us assume a normal ‘single' purpose MUSIC streamer (no ROON, DAC or Preamp) that needs to support an input stream of albums with File Formats of FLAC, ALAC, WAV, AIFF, MP3, AAC, OGG, WMA, WMA-L, DSF, DFF, Native Sampling Rates of 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz, 352.8kHz, 384kHz, 705.6kHz, and 768kHz and DSD formats of DSD64, DSD128, DSD256 and DSD512 including Bit Depths of 16 and 24.   I agree this is a lot of information.

What processing is the streamer doing on these files, for example, an AIFF coded album stream?    

FIRST, I know the streamer needs do to prepare the input for outputting USB, AES/EBU, etc. formats (I think).   Does this process require high amounts of processing power (probably yes)?  

SECOND, AND, in addition, what does the streamer do to the steaming input to prepare it to be accepted by the DAC?   Let us assume an AIFF Coded album.   What exactly is involved in preparing the AIFF Album file (or any of the other formats) for inputting to the DAC and does this require large amounts of processing power (probably yes)?

Your post above (and someone else's) said "It takes a tremendous amount of processing power to compute all the different ways digital has tried to keep up with analog“.  I think you are saying is that in order to support the large amount of input formats, high amounts of processing power is required to prepare the AIFF coded album for output to the DAC.  Is this correct?   

Assuming the above is true, it means the servers processing power is used to prepare the input data stream for correct formatting for the USB, AES/EBU, formats, etc. AND then format it, as needed, for input to the DAC.   Based on my understanding, I think this sentence answers my original question.   Am I correct?

Or, are there other processes going on in the streamer that requires high processing power?   If yes, what are they?   Thank you very much.


djones51
4,947 posts
 
To get back to the OPs question there is nothing going on in a dedicated  home based music server to necessitate the need for dual 20 core Xeon processors and 48 GB of ram unless you're starting your own streaming service. A NAS can run a music server perhaps not Roon but Plex or something similar. 
erik_squires
16,243 posts
 
Roon may over-estimate it’s CPU requirements, mostly because they want to specify a CPU that is capable of doing all the upsampling you might ask it to do.

I’m running an 8 y.o. AMD A10 with no issues, but if I attempt high level DSD sampling I won’t be able to. It also sounds bad IMHO, so I lose nothing.

Also, Roon does all the EQ and upsampling in the server, so for every DAC end point you need to account for that.
But overall, I think it’s pretty light. I’ve also seen Logitech Media Server run on routers. That’s extremely lightweight.
djones51
4,947 posts
 
Let us assume an AIFF Coded album.   What exactly is involved in preparing the AIFF Album file (or any of the other formats) for inputting to the DAC and does this require large amounts of processing power (probably yes)

Think of audio compression like a zip file, it's already been compressed the codec uncompresses then software and other firmware in the device send it on to the DAC. Unless some sort of manipulation of the file is being done like upsampling or EQ it's not a very CPU intense operation. 
erik_squires
16,243 posts
 
Here, take a look at the GNU gzip code:
https://savannah.gnu.org/projects/gzip/
That may help you understand. Every instruction takes CPU time.  The faster the CPU, the less time that instruction takes.

Best,
E
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