Same as the other one.
Ive been using Blackmagic Mini monitor for outputting SDI for a while now and overall happy but notice it can start to lag slow down computer and long amounts of time.
I have switched to a basic HDMI > SDI now without any problems.
PS We’ll have some added thoughts on this subject soon, as we are adding some support for eGPUs. Notes on that to follow. 
I’m still working on NDI to Raspberry Pi over ethernet. The Pi basically becomes a low latency RJ45 to HDMI adapter. (Rumors that NewTek will drop ARM support for NDI :( so it may be over soon ). But there is a working build of TCPSyphon to the Pi. Haven’t tested it yet!
Got a link to a tutorial on how to set this up? Or maybe make a new thread with instructions? Seems like a great usage of NDI.
At the moment NDI is broken on the Pi and NewTek isn’t helping. This forum link. Apparently the Pi isn’t powerful enough to support 1920x1080p60 NDI so NewTek isn’t working on it. If you want to test TCPSyphon to the Pi and back make a PocketVJ and keep up to date with the repo here. Marc just added OSC, and we updated the calls and there’s now a TouchOSC template for it.
Looks like they have a new (as of 091518) Embedded SDK with arm support. I just happened to be googling around this topic to see if I could put some older RPis to use.
https://www.newtek.com/blog/newtek-ndi-v3-7-what-you-want-to-know/
NDI got pulled from FFMPEG: https://trac.ffmpeg.org/ticket/7589?cversion=0&cnum_hist=11
From what others have said, the RPi’s might not have enough power to be a good NDI box. But NDI makes the spark and BirdDog makes a number of NDI boxes. http://www.bird-dog.tv/