Poor Network Performance when using a MAC as Audio-Server

[michaeljeger]

Hi

I encountered a really weird thing.
I set up my MAC (with OS X 10.10) to be my Audio-Server.
Attached to the MAC are USB3 disks.

When playing from the XXHighend PC (Win8), network performance is extremly slow.
Transfer speeds when playing flac files from the Audio-Server within XXHighend are about 1-2 Mb/s. So to load a track takes about 10 secs or even more.
The really strange thing is that this slowdown only happens within XXHighend. When I transfer a file from the Audio-Server to the XXHighend PC, I get transfer speeds of 50-60MB/s.
The only reason I could see that happening is the way XXHighend requests data from the server.

When using a Audio-Server with Win8 installed, network speeds are good and fast (about 30 MB/s).

Does anybody use a MAC for Audio-Server as well?
If yes, do you know what I am talking about / is there a solution?

Regards, Michael

[PeterSt]

Hi Michael, let's try ...

The major important one you most probably already use in well fashion, but we have to begin there ... :

When a connection is inherently slow all depends on the packet size (of transfer). So think very small packets and because of the two way communication needed for this, the overhead is huge. Now FLAC ...

FLAC itself is organized so that it *creates* small transfer "packets" (blocks). Notice this can be tuned, but this has already been done and is optimized within XXHighEnd. So we have two phenomena at hand :

1. A slow connection, especially on the two-way communication (blame the Mac here);
2. Small blocks of data to transfer (say blame FLAC now).

How to solve this ?
Avoid some whatever disk subsystem layer with the same interrupt usage or whatever it is I found. How ?
Play form RAMDisk.

I must assume that you already do this, but still it is no coincidence that you exactly mention what I know from the real slow connections (like WiFi) and which plainly is solved by means of that RAMDisk. But two requirements here :

a. XXHighEnd itself must be on a RAMDisk (and thus must be started from there).
b. The Playbask Drive must be on a RAMDisk.

When this both has been arranged for, you don't notice a thing of any slowness, not even at (I forgot) something like 1Mb ... ah ... I recall ... Bluetooth. So without this solution a track could take 1-2 minutes, and with this solution maybe 5-10 seconds.

What came from this solution for the very slow connection, is that I now generally tell that the RAMDisk playback etc. is a requirement for when playing over a network (NAS will be the same). So to my own surpise this seems even faster than loading music from an internal hdd. In the end it is all about that ... the hdd stuff which is super slow. Relatively. And what I expect is that the "processing" on the hdd for FLAC (all the small bits and pieces) sort of detach the network connection (or don't let it nicely flow) and the overhead for this now is too large to be acceptable.

Now tell me if this helps ...
Peter

[michaeljeger]

Hello Peter

Thanks for your answer.
I am really afraid that this is now a Samba problem and that probably nothing can be done unless XXHighend would transmit the file as a whole in burst mode.
Your assumption that I use a RAMdisk is right. However the slow portion is really the time it takes until the file is fully transfers.
Samba seems quite decent with big files in burst transfer but as soon as small files are transferred, it drastically starts to slow down.
I also compiled Samba3 and replaced Apples implementation of Samba to see if that was the problem.
The situation did not really change, still super slow.
So I would assume the Linus File servers will probably show the same slowdown and the problem is Samba related.

I think there will be no solution to this unless XXHighend would offer an option to do some kind of burst transfer of the file.

Regards, Michael

[PeterSt]

Michael,

I think it is not the biggest deal to make something like that ...

Thanks,
Peter

[michaeljeger]

Hi Peter

That would be for sure helpful.

In the meantime, I will hookup the USB-Driver to the XXHighend PC.

Regards, Michael