I have been getting some great advice from the people here as we stasrt our journey into the world of vmix. Recently we invested in a new system to replace our creaky old Mac Pro 8 core, which worked fine for live streaming but not so much for more studio based use.

Our new system:
based on a Scan Computers 3XS build - they put it together and send it.
X299 Assus Prime Deluxe Motherboard - with 5 PCI slots
i7 7820X
16GB RAM
Corsair 850W PSU,
SSD for OS (windows 10)
1tB capture drive - just a Barracuda
NVIDIA GT1060 6GB
Blackmagic Decklink Duo 2 (4 SDI inputs)
Blackmagic Decklink Studio Pro (1 SDI input)
Blackmagic Intensity Pro (1 HDMI input)

So far, we've been very impressed with the performance, we're recording 2 streams via the recorder, master out with 6 channels of audio via MAB WAV (4 from a BM mini converter Audio to SDI, +2 from BM DL Studio AES in) - for some reason the MJPEG codec is a bit wonky when it records more than 2channels - at least Vegas wont recognize any audio, 2nd record channel - a virtual input which we pan and zoom for CU shots and record to disc.

We're using MIDI to control the shots and other features from an iPad as we used to do with our ATEM system so no new muscle memory required.

Additionally we use Multi-corder - one for each BM input - 6 channels all using MJPEG codec.

So 8 channels of discrete video recording (wow!), + 6ch WAV. All to a regular internal regular drive (Barracuda), plus external monitors for multi-view and preview out to a screen at the back of the set for a backdrop.
This rarely goes above 30% CPU with 50ms render time.
EDIT: Update to 20.0.44 brings this down below 20ms
EDIT 2: Disabling NVIDIA services brings this down to under 3ms

Overall I'm pretty pleased with this and it renders at about 40% faster from our NLE (Vegas 15).

Not sure why the Magic YUV and Newtek codcs just look so bad though, very crushed blacks, another issue we get is when trying to add an NDI source from a laptop over 1gbit ethernet, it drops a lot of frames and introduces dropped frames the rest of the multi-corder channels even with a lesser number of discrete recorded channels.

We plan to add a 4K capture in the future so our pan/scan shot is of a higher resolution.

Anyhow, hope this is of some use to people looking to build a new system

What was your setup and how did it perform twidget?

Very interesting. Is this something you have played around with or is it official advice from Martin? Any suspected disadvantages to it?