Quick but fundamental question - please forgive my ageing analogue mindset. With regard to network traffic, does sending a flac file to three endpoints send three times the data over the network?
Er … that’s it.
TIA
Short answer: Yes
please look here. Switched from one endpoint to three in one group playing the same file. Data rate tripled. No surprise.
Ellaborating a bit on the resonse of Klaus, this is correct on your local network.
Assuming your are using a Roon server , if you stream a file from a streaming service, that will be transported only once via your internet connection.
Dirk
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Not really it will pull it once from the internet only but will still send out a seperate pcm stream to each endpoint. Therefore 3x bandwidth is used on the local network.
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Thanks people, appreciated. My 8 endpoints probably explains the occasional stoppage between tunes then.
Mustn’t grumble 
That could be a network thing, or a Core thing. What is your core’s cpu?
Processor Intel® Core™ i7-5557U CPU @ 3.10GHz, 3101 Mhz, 2 Core(s), 4 Logical Processor(s)
Network pretty solid, 7 of the 8 are ethernet Powerlines, one wireless.
And people are telling me to stay away from a 10g network as unnecessary. I’m streaming to a lot of endpoints!
Power lines and wireless won’t help. Powerlines are notoriously bad as dropping down speeds, they don’t really follow ethernet protocols either.
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Mine manages 8 no issues at all. Could go more if I wanted to I guess, no need for 10g.
It also depends on your network topology. Using locally/core stored streaming to all 8 endpoints simultaneously as an example, all that traffic would only flow in the segment from the core to the first switch. It may then split according to how you have the endpoints distributed in your network. As @CrystalGipsy has said though, Powerlines are potential trouble spots for smooth operation.
Just one remark here
If you combine 3 endpoints to one zone then the roon server will send only one stream.
AFAIK it sends three streams from the local server. This what I checked last night out of curiosity
Hi Chris - my stoppages only occur when multiple endpoints are grouped. My relationship with Roon takes three forms, adoration, frustration and confusion.
Today we have confusion
this is most interesting. I didn‘t test this myself and stand corrected.
I don‘t know the reason behind it. From a technical point it should be possible to use one stream for a combined zone
Yeah, I find a few things puzzling about zone grouping.
I know this isn’t the same, but Roon uses its own grouping method (which I think per above is to send a separate stream) when I group multiple Sonos zones. But Sonos has its own ability to group zones which is both more bandwidth efficient and more resilient over sonosnet. It also leads to some bizarre edge and corner cases when you try to pause grouped zones or play using the Sonos app to one zone that is currently playing from Roon. I do wish that when using Sonos zones, Roon used Sonos’ native grouping, and that Roon could “observe” what Sonos zones are doing natively (e.g. if my wife is playing Spotify on Sonos, I can see in Roon that the zone is busy, even if Roon isn’t the one playing and it can’t tell what’s playing); but I realize that is not exactly the same thing as being discussed above.
All x units in a zone will need the music feed one way or another. Assuming one of the devices in the zone becomes the ‘master’, that unit will have to beam the data to the other units in addition to keeping playback in sync, so zones will (at least to my knowledge, although I don’t know precisely how roon deals with zones) create traffic x times the number of playback devices no matter what. Please correct me if I’ve got this all wrong
Grouping endpoints is only possible with the same type.
If you have an endpoint of the type RAAT, it is not possible to group it with Airplay, or with Sonos Streaming.
How many streams are sent at the same time depends on the type of the group.
RAAT: Roon Core sends one stream directly to every endpoint. In this case it is the core which is responsible for the timing.
Sonos Streaming: Roon Core sends one stream to the master device and Sonos sends the multiple streams to the slave endpoints in the group. In other words Roon is using the Sonos grouping.
Airplay: Roon Core sends one stream to every endpoint. Roon only supports Airplay 1, which does not support grouping. Roon just sends the stream to every device, but there is no synchronisation.
All these streams work with unicast traffic.
This is the theory.
So. What type of endpoints do you have? Do you upsample on the Core? What is the maximum bandwith your powerline connection supports? With how many devices in the group do the dropouts begin?
Roon requires per stream:
- 44.1/16 (CD) = 1.5 mbps
- 96/24 = 5.5 mpbs
- 192/24 = 11-12 mbps
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Nice one Peter, many thanks - the fun continues!
Yes, but Roon allows for individual zone DSP even in a grouped zone. I send upsampled DSD to one endpoint, untouched 44.1 to another, and convoluted PCM Max power of 2 to a third. So, that wouldn’t work with only 1 stream. Roon allocates 1 core per stream for DSP purposes.