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NAS versus external disk


cfmsp
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Okay, let's hear it. What is the 'musical' rationale, if any, for using a NAS rather than an external disk connected directly to the computer (or via Airdisk feature of Airport Extreme)?

 

Just to be clear, things like backups, reliability, RAID capability, etc, don't count as 'musical' rationale, for purposes of this discussion.

 

I've been here a year now, and I still don't get it. :)

 

For extra credit, has anyone tested to see if Firewire (or eSata) connection to external disks has less impact on sound than the ubiquitous USB connection (given that USB is not a peer-to-peer interface and relies more heavily on the computer processor)?

 

 

thanks in advance,

clay

 

 

 

 

 

 

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I asked Chris some of these questions in e-mails. The reply is some what based on indirect tests, so not sure if it's rational per say. Chris can chime in if he fells the need. Basically, from the comparisons made at the symposium people seemed to prefer the os on ssd and music on hdd over the os on ssd and music on nas/hdd. From this its expected that e-sata would be better than the nas/hdd. I also asked about moving the nas from the back room and connecting it via usb and that seemed better in my situation. My nas is not exactly a nas as its really more a usb attached drive on a network. Elosie pointed that out to me and well she was right....

 

Regards

 

Jesus R

www.sonore.us

 

 

 

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Hey Clay,

 

I assume the eSata (or just SATAII for that matter) to sound the best because it is the most under the control of the OS without overhead. This is all rather indirect stuff and in my case I anticipate "best scenarios" like nothing needing that disks after playback has been initialized, so this disks will spin down and the OS won't have to deal with them anymore whatsoever. I know, I know, I'm not talking about random players here. :-)

 

Even when the music would be streaming continuesly (or semi because of larger "buffers") I estimate an (e)SATA connection to be the best for SQ because of the least overhead. Also think about it being the fastest connection possible, so whatever the "overhead" is, it is away the fastest of them all.

 

For me these things are just theory because I never tried it (using SATA only anyway). But because everything following the theory of "less consuming sounds better", it is my guess this will count here just the same.

 

Don't come up with something like WiFi !

 

Peter

 

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JR says:

"My nas is not exactly a nas as its really more a usb attached drive on a network."

 

By NAS, I'm referring to network-attached-storage, per...

 

http://en.wikipedia.org/wiki/Network-attached_storage

 

...and in particular any device that has it's own OS (however limited it might be), but NOT to include the peer-to-peer communication abilities of Firewire (about more of which in my response to Peter).

 

Your configuration is like the Airdisk feature of the Airport Extreme I refer to above.

 

thanks for sharing what you'd heard from Chris.

 

Clay

 

 

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Peter, as always, thanks for your considered reply.

 

"I assume the eSata (or just SATAII for that matter) to sound the best because it is the most under the control of the OS without overhead."

 

Understood about eSata as compared to USB, for instance, but I'm wondering if there's any significance to the fact that Firewire uses NO CPU or Memory to transmit data 'peer-to-peer' from one device to another. [reference cited below for those who keep wondering if Firewire is everything Clay keeps suggesting it is.]

 

Given that, firewire would seem to have a theoretical advantage over even eSata (Sata II), yes?

 

Clay

 

 

"It allows peer-to-peer device communication — such as communication between a scanner and a printer — to take place without using system memory or the CPU." per:

http://en.wikipedia.org/wiki/IEEE_1394_interface

 

 

 

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The biggest misunderstanding always (or the most often at least) is that people think this (SQ) is about CPU ...

 

It is merely about interrupts. Interrupts and the swapping of the CPU's cache.

 

What you describe about Firewire may be true about disk to disk transfers, but how do you see that in operation here ? There is no such thing in order I think. It is the PC needing data from the disk and it is going from the disk to the PC's memory. I don't think any additional smartness of Firewire can help here, since disk controllers (like on the PC's mobo) are as smart for *that* job.

 

Of course I am not considering tasks the PC could do during playback; that would be a complete other matter !

 

Peter

 

Lush^3-e      Lush^2      Blaxius^2      Ethernet^2     HDMI^2     XLR^2

XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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Thanks Peter.

 

"The biggest misunderstanding always (or the most often at least) is that people think this (SQ) is about CPU ...

 

It is merely about interrupts. Interrupts and the swapping of the CPU's cache."

 

As everything is 'connected' and potentially impactful on every other aspect (of a computer-based digital audio playback chain), once again a thread seems to digress onto another topic.

 

Peter, I have to respect your opinion here (as you've chased your curiosity all the way to a hands-on creation of a software player), but I should point out that there are at least 4 schools of thought related to your point above.

 

1) Some believe that every bit (no pun intended) of processing in the computer can lead (cumulatively, if nothing else) to extra noise/RFI/mysterium/etc. and thereby affect the sound.

 

2) Others believe as you have stated above - it's about minimizing interrupts and swapfiles.

 

3) Others believe that we just don't yet know.

 

4) ...and still others believe that it doesn't and can't matter (I'm thinking of the 'bits is bits' HydrogenAudio crowd).

 

 

Are you truly in camp number 2? I thought you had shown a difference in output of your player due to use of graphical interface?

 

even your comment above suggests not.

"Of course I am not considering tasks the PC could do during playback; that would be a complete other matter !"

 

If it were only about 'interrupts', wouldn't the compromised sound quality occur only at the moment of the 'interrupt' rather than continuously?

 

Couldn't a significant background task (not in the signal path of the playback chain) affect processing in a similar manner to a continuous series of interrupts (whether via noise/EMI/mysterium/etc.)?

 

very curious as always,

 

clay, still in camp #3.

 

PS, 'mysterium' is just a made up name for heretofore unidentified factor.

 

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I think you nailed it! I believe....I believe....sorry :) With name like Jesus one has to believe in something! Seriously, I believe in 1,2,3! If Im going to build a machine and it only takes a few minutes to enter the bios and disable something I don't even use that is what Im going to do. Same thing with the interrupts. Peter has done a nice job on his site of walking us through that process and why not attempt it, especially on a dedicated audio unit. Then what do we really believe in if the process can be proven to be bit perfect. I guess we are back where we starte. I'll pass on 4. One of my relatives says wires don't make a difference. For him this is a fair and true statement as he can't hear that well from years of load noice exposure....hahaha.

 

Regards

 

Jesus R

www.sonore.us

 

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"Seriously, I believe in 1,2,3!"

 

very good point, JR, I guess I am in all three camps (aka schools) as well, so presumably they're not mutually exclusive, excepting for camp 4. ;)

 

There's certainly much that I don't yet understand, which automatically puts me in camp 3, given my nature, but I am starting to believe (if actions truly do speak louder than words, I'm already there!) in camps 1 & 2, without demonstrable evidence, I might add.

 

but hey, that's why we're all here!

 

clay

 

 

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Hi Clay,

As always you think quite well about everything, and together with my lousy writing you may end up at 3) automatically.

:-)

 

When I said (and implied) it isn't about CPU useage I meant to say : even processes which don't use CPU interfere with SQ because they interrupt.

And related is : for players which don't even use CPU that can be proved, how would using CPU (by others) matter ?

 

So, these both lead to interrupts doing the nasty job by itself, BUT, also knowing what it takes to swap the CPUs cache (hey, I don't even know whether *that*officially consumes CPU !).

 

All together, I am not only in camp 2, but just the same in camp 1, but not because it may interfere with playback (if that does, it would incur for glicthes and the like), but now because it "consumes". This is the PSU matter. BUT :

 

This latter is only to be assumed because nobody can think of another reason (that I know of) so for that matter I may be (and honestly) in camp number 3 just the same. Be careful now, because my camp 3 is about "Don't know WHY" and not about "don't know YET". The yet it definitely sure (a few seconds matter !), but the how needs education beyond me (for some subjects that is, hahaha).

 

If it were only about 'interrupts', wouldn't the compromised sound quality occur only at the moment of the 'interrupt' rather than continuously?

 

Well, since something like a PC may swap tasks each few ms, let's be careful what "continuously" means here (and remember a CPU operates at the GHz rate, so any task gets a sufficient amount of cycles in the mean time !).

 

Couldn't a significant background task (not in the signal path of the playback chain) affect processing in a similar manner to a continuous series of interrupts (whether via noise/EMI/mysterium/etc.)?

 

Yes. But as said, this will never be the base for good sound, and nobody will do that. So, this *is* the CPU useage, but now for drawing current (in a not even way).

Btw, I regularly read about a CPU useage of "only 60%, so what can be the problem". Well, besides this is crazy (ditch the player), this is a most wrong base for good sound, because now the playback itself draws the current. If this is the case, there's little chance sound can be improved by removing other processes, my they consume CPU or interrupts only.

 

Let me end this little 1,2,3,4 by saying that all is far from easy; You mentioned the swap file ... well, I can show you a thread which indeed may show a swapfile is interfering, but in a way just nobody can guess or even reason out afterwards.

 

Computers ...

Peter from camp 3. a.o ... :-)

 

 

PS: Nice subject about the disks. Now, who is asking the question WHY an SSD matters so much ? I think if the answers to that are very clear, the answers to the disks (how to connect) are far more easy.

 

 

 

 

Lush^3-e      Lush^2      Blaxius^2      Ethernet^2     HDMI^2     XLR^2

XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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"As always you think quite well about everything, and together with my lousy writing you may end up at 3) automatically.

:-)"

 

Peter,

thanks for your well thought out reply also. I'll admit that the language issues can be a bit of a problem, but...that said, it's also a blessing in some manner of speaking. It requires really trying to understand precisely what you are saying as a whole, and thus avoids focusing on any particular 'turn of phrase'.

 

I see a lot of miscommunication online as a result of hasty readings where the reader has focused on (disagreement with) a single phrase, to the detriment of actual understanding of what was being communicated, and often taking a couple of emails to sort out, maybe even including an apology. ;) I'm guilty as well. One could argue that this is what I did in my earlier reply. :)

 

thanks again, I hear where you're coming from, loud and clear.

There's still lots to figure out here.

 

clay

 

 

 

 

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