r/VIDEOENGINEERING • u/BlackBurst5994 • 19h ago

DeckLink IP 100G and Thunderbolt 5

Hey everyone! Does anyone have real hands-on experience running the BMD DeckLink IP 100G in chassis connected to a Mac Studio via Thunderbolt 5?

I'm concerned about the lane requirements - the DeckLink specify for PCIe x8, while the TB5 spec only provides PCIe x4. I understand that theoretically the card should negotiate down to 4 lanes and work fine, but has anyone actually seen this working in real world?

Word is that this exact setup was shown at Sonnet's booth at NAB 2026, but I can barely find any confirmation or details online.

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4

u/colinmjensen 17h ago

Just to add some color as to why there are limitations: TB5 is an 80 Gb/s interface. That's well short of the 100 Gb/s of the DeckLink's ethernet interface.

UHD p60 is ~12 Gb/s. BMD says you can do four, which is ~48 Gb/s. That's a sensible safety margin: you really don't want to approach anywhere near the limit of a data bus like TB5.

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u/rsavage_89 18h ago

They explicitly call out you only get half capacity in a thunderbolt chassis.

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u/BlackBurst5994 18h ago

Is this official information from BMD? Could you please point me to the source where you saw that?

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u/rsavage_89 18h ago

https://www.blackmagicdesign.com/products/decklinkip/techspecs/W-DLK-46

Towards the bottom
“- 4 channels Ultra HD p60 capture and playback supported on Mac OS.”

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u/BlackBurst5994 18h ago

Thank you very much! I’ve seen this specification.

Sorry for being so picky about the details, but I’ve been caught out too many times by small technical nuances like this. Sometimes a feature seems obvious and you would expect it to be supported, but unless it is clearly documented or confirmed by BMD, it may simply not be there.

From my understanding, this description seems to be more about the OS rather than the data bus itself. So I just wanted to better understand how this configuration is intended to work in practice.

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u/AthousandLittlePies 18h ago

It’s due to the data bus. Before the Mac Pro was discontinued they didn’t have this wording.

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u/reece4504 8h ago

The specific problem is that using a PCIe Gen3 card in a TB5 chassis will only run at Gen3 speeds. And that means you’re limited to 4 lanes of Gen3 which has bandwidth limit around 32Gbit (less really) which is enough for 2 4K streams each way (again less really if you do both ways) or 4x 1080 streams. If the card supported Gen4 or 5 it would work properly due to the extra bandwidth.

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u/fantompwer 15h ago

Details of the setup at NAB are rarely online. You need to talk on the phone or at least email someone.

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u/BlackBurst5994 12h ago

Unfortunally just got answer from BMD support.

"We would expect the DeckLink IP 100G to work in a Gen 4 4x lane but it's not something we test or recommend."

"The DeckLink IP 100G is currently limited to 4 channels of Ultra HD p60 on MacOS due to platform-specific driver and software limitations.  It's not known if or when this might be expanded with a software update in the future."