Carbon AVB Ethernet max throughput

[K Roche]

Originally Posted by dominicperry

AVB on the Carbon runs at 1Gb/s. There is no need for you to use a 10Gb/s port on your Mac, as it will auto-detect and run at 1Gb/s when the Carbon is connected.

No switches (not even AVB switches) are qualified by Avid to work with Carbon.

You are not meant to connect other devices to the AVB ports on the Carbon, except Carbon Pres.

Dominic

Humm,, Interesting-- 1 Gb/s for the Carbon ? I did not know that, for some reason I thought I ordered my iMac with the 10 Gb/s ethernet port, specifically to use with Carbon ???? (but I could be mistaken) ... . is that stated somewhere in the Carbon info and I simply missed it ?

[dominicperry]

Originally Posted by K Roche

Humm,, Interesting-- 1 Gb/s for the Carbon ? I did not know that, for some reason I thought I ordered my iMac with the 10 Gb/s ethernet port, specifically to use with Carbon ???? (but I could be mistaken) ... . is that stated somewhere in the Carbon info and I simply missed it ?

You may have ordered your iMac with an AVB compliant Ethernet port but the Carbon only has 1Gb Ethernet ports.

EDIT: I just discovered on 06Feb23 that the Carbon Pre doesn't support more than 8 channels of I/O. That's right, if you are using the analog ports, you can't use the ADAT. So all the calculations below are excessive because you can't actually use anything like that many channels. I'll leave the rest of the post for posterity.

It doesn't matter - the maximum sample rate of the Carbon is 192KHz. At that sample rate, you get 8 analog channels and 4 ADAT channels per Carbon/Carbon Pre. Making 12 channels of audio per device. You can have a maximum of 3 devices (Carbon+Pre+Pre). So that's 36 channels.

Using the Sound Devices calculator (https://www.sounddevices.com/audio-r...ng-calculator/) you will see that 36 channels of 32bit, 192KHz audio is ~221Mbps.
Alternatively, if you use 96KHz, you get 8 analog + 8 ADAT channels per device. So 16 x 3 = 48 channels of 32bit, 96KHz audio is ~147 Mbps.
Alternatively, if you use 48KHz, you get 8 analog + 16 ADAT channels per device, so 24 x 3 = 72 channels of 32bit, 48KHz audio is ~110Mbps.

1000baseT (i.e. Gbit) Ethernet is always full-duplex, so you get 1Gbps in each direction, so there's no need to calculate ins and outs - it's the same figure in both directions, simultaneously.
I don't think the Carbon system actually supports more than what is described as a 28x56 config (at 192KHz) but either way, whether it's 56 channels or 72 channels, there's clearly enough bandwidth to carry all that audio across a 1Gb Ethernet link.

If you want to know how I'm so sure about the speed of the Carbon Ethernet port, when I was sent an early version of the Carbon firmware, I had to install it via a web interface that is normally hidden from users. That allows me to see the config of the physical box.

Dominic

[K Roche]

Originally Posted by dominicperry

You may have ordered your iMac with an AVB compliant Ethernet port but the Carbon only has 1Gb Ethernet ports.

It doesn't matter - the maximum sample rate of the Carbon is 192KHz. At that sample rate, you get 8 analog channels and 4 ADAT channels per Carbon/Carbon Pre. Making 12 channels of audio per device. You can have a maximum of 3 devices (Carbon+Pre+Pre). So that's 36 channels.

Using the Sound Devices calculator (https://www.sounddevices.com/audio-r...ng-calculator/) you will see that 36 channels of 32bit, 192KHz audio is ~221Mbps.
Alternatively, if you use 96KHz, you get 8 analog + 8 ADAT channels per device. So 16 x 3 = 48 channels of 32bit, 96KHz audio is ~147 Mbps.
Alternatively, if you use 48KHz, you get 8 analog + 16 ADAT channels per device, so 24 x 3 = 72 channels of 32bit, 48KHz audio is ~110Mbps.

1000baseT (i.e. Gbit) Ethernet is always full-duplex, so you get 1Gbps in each direction, so there's no need to calculate ins and outs - it's the same figure in both directions, simultaneously.
I don't think the Carbon system actually supports more than what is described as a 28x56 config (at 192KHz) but either way, whether it's 56 channels or 72 channels, there's clearly enough bandwidth to carry all that audio across a 1Gb Ethernet link.

If you want to know how I'm so sure about the speed of the Carbon Ethernet port, when I was sent an early version of the Carbon firmware, I had to install it via a web interface that is normally hidden from users. That allows me to see the config of the physical box.

Dominic

Thanks for the detailed reply Dominic much appreciated I must have just assumed more (10 Gb/s) was better
The only reason I was wondering,,, was because I have never had any of the (lost connection) issues that some are reporting but maybe that is actually and unrelated issue

[MarkH]

If anyone thinks AVB is hard, be glad you're not in the world of Dante with routers, VLANs, QoS policies, and domains

Most Dante devices are 1Gb only. Some Dante Video will use 10Gb but typically the hosts are 1Gb and the upstream aggregate links may be 10Gb. Also 10Gb isn't "faster" than 1Gb unless the network is congested. Packets arrive from Host A to Host B at exactly the same speed when using the same network infrastructure and cable distance on both 1Gb and 10Gb.

[dominicperry]

Originally Posted by MarkH

If anyone thinks AVB is hard, be glad you're not in the world of Dante with routers, VLANs, QoS policies, and domains

Most Dante devices are 1Gb only. Some Dante Video will use 10Gb but typically the hosts are 1Gb and the upstream aggregate links may be 10Gb. Also 10Gb isn't "faster" than 1Gb unless the network is congested. Packets arrive from Host A to Host B at exactly the same speed when using the same network infrastructure and cable distance on both 1Gb and 10Gb.

I'm an ex-wide area network engineer, so that stuff is fine, but I do get completely boggled when people start talking about routing in DADman and using objects and beds in Atmos. I'm going to stick with stereo for a while longer..........

Dominic

[QuacksMeUp]

Wait… stereo? I’m still getting the hang of mono!

[MarkH]

Originally Posted by dominicperry

I'm an ex-wide area network engineer, so that stuff is fine, but I do get completely boggled when people start talking about routing in DADman and using objects and beds in Atmos. I'm going to stick with stereo for a while longer..........

Dominic

Yes! Why can't there be a CLI for that.

# config t
# interface atmos | range 7.1.4
# interface range 1-12
# exit
# end
# show atmos
# copy run start

[dominicperry]

Originally Posted by MarkH

Yes! Why can't there be a CLI for that.

# config t
# interface atmos | range 7.1.4
# interface range 1-12
# exit
# end
# show atmos
# copy run start

I'm going to pretend I don't recognise any of that...................

[dominicperry]

Originally Posted by QuacksMeUp

Wait… stereo? I’m still getting the hang of mono!

I'm quite fond of a bit of glorious mono.