Hi All.
Thanks for take a moment to read this post. We have same big issue with two vMix units

Unit Number one & two
I7, 7700, 32GB RAM
ASRock Motherboard Z270 Extreme4

Unit One:
DeckLink Quad 2
DeckLink Duo 2
DeckLink Studio 4K

Unit two
DeckLink Duo 2
DeckLink Mini Monitor 4K

Our problem starts when we add camera number 4. systems runs smooth and solid with 3 cameras, but when we add 4 and up, starts a kind of strobe, lipsync is lost. We are using Blackmagic Sync Generator as well. Weird thing is if we add the camera number 4 on the second card there's no problem.
Example: Deckink Quad 2: inputs: Camera 1,2,3 Running Smooth. Adding camera number 4 Starts video sync problems and strobe. But if we add the camera number 4 to Decklink DUO 2 we can support Up to 6 cameras. But the weird thing is. If we are on Quad 2, Camera 1, 2, 3, and camera 4 on duo 2 we can add more inputs as well as hyper decks, Aja Ki Pro up to complete 8 inputs. Same thing with decklink duo.

We have the same issue with Computer N2.

someone knows if blackmagic cards just supports up to 3 cameras and then issues starts?

Regarding our job, sequences must be: 1080i 59.94. Cameras are in 1080 59.94 as well.

Please, let me know if anyone knows any trick to deal with this.

Thanks in advance

I would also look at how many PCI-E lanes are being used. I have an ASRock z170 motherboard and it seems to be picky with which slot my cards are installed. And although I don’t have the same card, my BlackMagic Intensity Pro cards are more finicky than my Magewell.

CPilcher

I'm having the same issue with a new equipment. This had any solution? because I see it happened 3 years ago.

The problem is the same: Adding 3 inputs, the system run smooth. When I add the 4th input, it becomes to strobe, if I add another input, the effect it's every time worse.