As you know, vMix can stream to several points at the same time, but with one limitation — it will be the same content. That is why it is impossible to do multi-camera streaming on YouTube using this tool.
With NTRStreamer, you can stream DIFFERENT content from the same vMix. This is because vMix allows you to have different NDI outputs (with different content).
It’s not a secret that encoding during streaming can require many resources and affect the stability of the whole vMix.
NTRStreamer makes it possible to unload vMix.
Moreover, since NTRStreamer is a separate process, you can run it on another video card and use it for HW encoding. For example, you can use a GPU from Nvidia for vMix, and an integrated Intel graphics card for NTRStreamer.
Encoding on another PC
If your PC has streaming issues, then there are two options:
To upgrade it to more CPU and GPU
To transfer streaming to another PC (also not very powerful).
NTRStreamer is used in the second case. It allows you to transfer the “heavy” streaming process to a separate PC. In addition, in this configuration, streaming can go through another Internet channel.
Even an Intel-based netbook with HW encoding technology can be such an auxiliary PC.
This scheme may be relevant for game streaming: streaming from the same PC during playing can seriously affect the comfort of the game process (fps subsidence).