I know this may not be a vMix issue, but it is a show-stopper in configuring a new system specifically to run vMix.

Assembling a high-end I7 system to run V-mix. Planning on using NDI for most camera inputs, but including a BMD DeckLink Quad 2 to input legacy SDI video. Everything seems to work OK so far, but we haven't even got to the NDI inputs yet. The system runs great until we plug in the DeckLink Quad 2 board. At that point: (1) the ability to stream (receive) video from YouTube or Vimeo simply hangs DEAD. (2) And even playing a local MP4 video file is slow and stuttering when played with Win10 Video player, or Windows Media Player. And sometimes(!) using VLC player.

Inputting video from an SDI source into V-mix with the DeckLink Quad 2 appears to work OK, despite the other symptoms. Removing the DeckLink Quad 2 board returns everything back to normal. Except, of course, we can no longer add SDI video inputs.

Yes, we are running the latest drivers for the DeckLink Quad 2 board (Desktop Video 10.9.3), and the latest drivers for the video card (Asus-branded NVIDIA GeForce GTX 1060 6GB) 21.21.13.7878 as identified by Windows Device Manager. This is a brand-new system that isn't even in service yet, running the latest vMix version.

Thanks, @wildeeep

We plan on having 4-5 NDI camera inputs and perhaps 2 (essentially static) NDI graphics inputs.
We have an i7-6800K Processor
We were just playing videos from YouTube (an Vimeo) directly in Chrome browser without Vmix running.
Even playing a local video file was very problematic when the Quad 2 card is installed.
We figured that was a pretty easy test, but when the Quad 2 card is plugged in, it brings the system to its knees.
Doesn't have very positive indication of how things will work when running Vmix with many inputs.

Others have suggested that there might be an issue with which slots the Quad 2 and video cards are plugged in to.
However, we have tried EVERY possible combination of slots and everything works fine.
Until we plug in toe Quad 2 (to ANY slot) and it causes these show-stopping symptoms.

Hi, @IceStream

We have a ASUS X99-A/USB 3.1 motherboard. This is a newly-assembled system, not 2 months old.

The system seems to work great until we plug in the DeckLink Quad 2. At that point we can't even play online video on Internet Explorer or Chrome from either YouTube or Vimeo. And can't even play a local video file, either. The DeckLink Quad 2 DOES work to input HD-SDI video into Vmix. But this problem seems to be a bad omen, not to mention being very inconvenient to be unable to play video.

The complete system configuration is:

* Intel Boxed Core i7-6800K Processor (15M Cache, up to 3.60 GHz) FC-LGA14A 3.4 6 BX80671I76800K
* ASUS X99-A/USB 3.1 ATX DDR4 3300 (o.c.) Intel LGA 2011 Motherboard
* ASUS GeForce GTX 1060 6GB Dual-fan OC Edition VR Ready Dual HDMI DP 1.4 Gaming Graphics Card (DUAL-GTX1060-O6G)
* G.SKILL Value 32GB (4 x 8GB) 288-Pin DDR4 SDRAM 2400 (PC4-19200) Desktop Memory Model F4-2400C15Q-32GNT
* Blackmagic Design DeckLink Quad 2 8-Channel 3G-SDI Capture and Playback Card, 720p/1080p Cross-conversion
* SanDisk Ultra II 960GB SATA III 2.5-Inch 7mm Height Solid State Drive (SSD) with Read Up To 550MB/s- SDSSDHII-960G-G25 (for boot/system)
* WD Red 4TB NAS Hard Disk Drive - 5400 RPM Class SATA 6 Gb/s 64MB Cache 3.5 Inch - WD40EFRX (for video storage/editing)
* Samsung 960 PRO Series - 512GB PCIe NVMe - M.2 Internal SSD (MZ-V6P512BW) (for video recording)
* EVGA SuperNOVA 1000 G2 80+ GOLD, 1000W Fully Modular NVIDIA SLI and Crossfire Ready 10 Year Warranty Power Supply 120-G2-1000-XR
* Corsair Hydro Series H115i Extreme Performance Liquid CPU Cooler , Black
* NZXT PHANTOM 630 Windowed Edition Full Tower Computer Case, White (CA-P630W-W1)
* Rosewill 2-Port USB 3.0 4-Port USB 2.0 Hub eSATA Multi-In-1 Internal Card Reader with USB 3.0 Connector (RDCR-11004)
* Intel Gigabit CT PCI-E Network Adapter EXPI9301CTBLK
* Microsoft Windows 10 Pro (64-bit, OEM DVD)

I must admit that I'm not a great fan of software-based video production systems, and this experience has done nothing to improve my negative impression.

I would suggest you check the number of plié lanes available for the slot you are using for the BM card. You may need to change the slot. I have tested a BM quad 2 and Duo 2 at the same time for a total of 12 inputs with no problem on an Asus x99 .Just make sure enough plié lanes are available. The 6800 only has 28. You may need to change the processor to a 40 pcie lane version.

Max

X99 has nothing to do with this.