1 Topic by Kubrak (edited by Kubrak 2024-01-25 20:04:45)

  • Kubrak
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Topic: Digiface USB - how many may be used?

How many units of Digiface USB may be used together on one computer?

I know that up to 3 RME devices may be used on one driver. But is not there some limit on channels USB is able to transfer. And if three Digiface USB is possible, do they have to be on separate USBs? Computers have also internal USB hubs....

Has anyone used three DF USBs on one computer?

EDIT.
I have found on RME forum that USB2 has limit 70 channels in and 70 channels out. And 3 DF USBs have 96 ins and 96 outs...

  • ramses
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Re: Digiface USB - how many may be used?

RME tests up to 3 devices max, therefore this number is in the manuals.
Can be more or less depending on your PC and max number of channels, mainly because of
- CPU power (nowadays not an issue)
- DPC latency, more an issue, also depending on the max number of channels.
- USB infrastructure (best an USB controller dedicated for each of the recording interfaces)

Please keep in mind that DF USB has no word clock. One device needs to be the clock master, and you need to distribute the clock through ADAT connections between all devices.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13
  • Kubrak
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Re: Digiface USB - how many may be used?

I know about WC. I do not ask for myself, but for a guy that would like to use three DF USB.

Three DF USBs have 96 ins and 96 outs and has USB2. RME writes about 70in & 70out limit for USB2. So, it looks like 3 DF USBs cannot be fully used. In best case when everything works.

Or do they mean 70/70 for each USB connection, not for the entire driver?

4 Reply by ramses (edited by ramses 2024-01-25 21:42:56)

  • ramses
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Re: Digiface USB - how many may be used?

MADIface USB ... 68 ch in and 68 ch out .. supported by USB2.
This is about the maximum what is possible, or lets round it up to 70 IN and 70 OUT.
Digiface USB has 32ch in and 34 out.
So it might be possible to connect two Digiface USB behind one USB2 controller.
So to say threee Digiface USB behind two USB2 controller and one is shared by two DF USB.
To be on the save side I would recommend to connect each of the DF USB behind a dedicated USB2 or USB3 controller.
USB3 is fully backward compatible.
Note: USB3 doesn't give you more USB2 bandwidth, USB2 in an USB3 plug has dedicated plugs for USB2 (only).
At the end it might depend on the PC .. whether it is capable for such a setup.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

5 Reply by Kubrak (edited by Kubrak 2024-01-25 22:27:17)

  • Kubrak
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Re: Digiface USB - how many may be used?

OK, so 70in/70out limit is for per USB2 controller, not for the whole driver as I mistakeingly thought....

So, it might be possible to run 3 DF USBs if one meets the requirements, you mention. Thanks.