We're running into an issue where one 1080p59.94 video stream looks and sounds great, but once we add a third, it starts dropping video frames and the audio starts skipping. Once we add a fourth and fifth, the system really takes a hit. This leads me to believe there might be some sort of physical bottleneck between the card and vMix? We also have a bunch of other sources coming in NDI as well that look and sound great; the system in general is running smoothly.

We've monitored these streams independently just before going into the card, and they look and sound good.

We're using a Decklink Quad 2 and Z390 AORUS PRO WIFI mobo.

I'm wondering if we may need to go into a different PCI-E slot? Maybe something else I'm missing?

Thanks!

Here's the processor and gpu we're using.

Intel Core i7-8700K Coffee Lake 6-Core 3.7 GHz

GeForce RTX™ 2080 GAMING OC WHITE 8G

Thanks Tom, I'll be able to test these changes Tuesday and get back to you!

The only other inputs we're using is an NDI feed of the same signal. That brings us to a total of 10 inputs - 5 sdi, 5 ndi. Those 5 sdi are the only inputs on that decklink card.

-E

That is not necessary for a single capture card as x8 for the GPU + x8 for the capture card is plenty of bandwidth.
Instead, double check to make sure the capture card is installed in the second x8 slot and not the x4 slot at the end of the motherboard.

It does not need 16 lanes for vMix purposes. x8 is more than sufficient.