Trust me, I understand what you're trying to do.
When the video comes from the source into your new device, it has to be compressed/encoded NDI on the fly so it can be output to the switcher.
https://www.cpubenchmark.net/mid_range_cpus.html
(4000 passmark range CPUs)
The encoding takes CPU processing power. See the big text below. 30% of an i7 6700 for decoding (I assume encoding is even more). So you need something in the 4000 passmark range, at least.
The computer system I spec'ed out for you is an SFF PC. See the red text below.
http://forums.vmix.com/default.aspx?g=posts&t=7077
Is it GPU or CPU based?
NDI encoding/decoding is CPU based using around 5% per 1080p30 camera on a modern i7 CPU.
What color spaces are supported?
Frames are sent/received from NDI at 4:2:2 8 bit, but NDI compresses at 16 bit internally.
NDI also has full support for alpha, sent as a separate channel. (so 4:2:2:4)
Will there be converter boxes?
More than likely, possibly from more than one manufacturer.
We are working on our own prototypes
using off the shelf SFF (small form factor) PCs, but
the codec can theoretically be used on devices as small as a standard HDMI to SDI mini converter.
The main advantage of one of these converters is you will no longer need a capture card
opening up most laptops to multi camera productions without the need for thunderbolt!
My hope is the converters will be affordable.
What is the stream bitrate?
To my knowledge it is variable bit rate.
I've seen around 50Mbps to 100Mbps per camera in my tests so far.
...
I think "around 5% per 1080p30 camera" was quite optimistic, my own experience is that NDI uses a lot more resources than a capture card input.
Martin told me at IBC the NDI version 2 will be better when it comes to resource usage.
...
It seems to me it's using 20-30% cpu of an i7 6700 per NDI source on decoding - not encoding.
I'm just wondering if there is anything i can do on the vmix machine to ease up the decoding ?