Hey Folks,

i have a brand new system with the following specifications:

CPU: Intel i9-9900K
MB: GIGABYTE Aorus Z390
GPU: NVIDIA GeForce RTX 2060 SUPER
RAM: 32 GB DDR4-3200
OS: Windows 10
Capture: 2 x Blackmagic DeckLink Duo 2

When i open up a new vMix preset with 2 External Outputs (SDI 1080 50i) on the DeckLink Cards, my render time jumps up to 23 ms and higher with just 7 overall inputs (4 Cameras / 2 Videos / 1 graphic) and no 2nd monitor.

I just worked on the hints of vmix https://www.vmix.com/kno...nosing-high-render-times but could not find any of these problems on my computer.

Thanks guys if somebody can help me out.

Unless you absolutely need external on the Decklink for chroma, you'd better use the outputs of your graphic card or NDI as already suggested

Are both your Decklinks running at x4? There is a stipulation with the third PCI-E slot for that motherboard:

I would still use GTX outs with HDMI to SDI converters for such a workflow... even at the expense of 1 extra frame latency...

Same here. I only use extra display ports out for local client outputs. Used all 5 last week for various people. But anything going to stream and records is an External output via AJA SDI.

We have 5 vMix systems integrated into our broadcast facility at my day job. SDI output is perfect for us and I wouldn't do it any other way. Reference is a must for us (yes, I know there are also converters that can accept reference) since they are used with production switchers. I went from a spaghetti factory of a CAD drawing to 2 rectangles and some lines (the second being a Dante AVIO for AES67 connectivity to a Riedel Artist 128).

One of our systems exists strictly to take an SDI input, delay it, lay an animated bug over it, and then output it over SDI. We forget about that system weeks at a time, and that's with knowing that there are people who will raise a stink the moment there's something wrong with the output.

And all these systems use ancient Decklink SDI and Decklink Studio cards... in tandem in each system since they can't do unique outputs while capturing.

With your given configuration, I think it's unlikely that either card is running in X2. But you can use a program like HWiNFO to verify as well as get the lay of the land of your system. Here's what my DeckLink Duo 2 looks like:


If you haven't already, try a single DeckLink card at a time in each of the slots and see if you get different, and hopefully better results. It's entirely possible that there's just too much going on with that part of the chipset to properly accommodate the card. I'm saying this in horrible layman's terms.

I would also start with a new preset, establish your 2 external outputs, and then gradually add your sources. It may be useful to see when the render time starts to creep up, assuming it's not from the get-go.

Another thing that has just come up: Martin pointed out there's some performance issues with the more recent Nvidia drivers. You'll probably want to check yours and make sure it's version 452.06 or earlier.

As for high performance output mode: don't be afraid to try it. The worst that can happen is that you'll need to turn it back off. For me, in several instances I had improvements in dropped frames, particularly with multicorder, when enabled. I also run vMix in high priority.

If you're at the end of your rope, there are still other ways out. You can enable NDI on the necessary outputs and use another system with Newtek NDI Connect free edition to turn that around to DeckLink SDI output. Obviously it's more stuff to deal with, like an extra system and DeckLink card(s) you may or may not have. The preference would be to resolve the existing issue.

The same way as for any audio outs > in audio outputs settings > just select the Nvidia Output as the device to use.

I've two ryzen systems, and experiencing similiar problems on one device.

Do you have any updates on your problem? Have you resolved the issues?