NOTE: You need change IP and streamid for your value
You can run many commands (with different streamid) at same time for generate many feeds.For example I run 4 feeds to check my notebook for HD@25fps feeds:
Notebook with Core-i5 uses 17% for 4 streams of HD@25fps/2Mbs
Example: Run few streams from macOS
Don't use Preview window long time
Built-in Preview window takes CPU for rendering, so no reason use it on slow PC long time. In our test we got increase CPU usage from 17% to 35% when open Preview window