HW Dec used but all cpus at 100% (8 streams)

I created 8 pipelines:
uridecodebin->nvstreammux->queue->nvvidconv->capsfilter[video/x-raw, formt=(string)NV12]->jpegenc->appsink.

Is this behaviour cause by jpegenc?

What causes the cpus’ to be at 100%.

Below is the link to the image.
https://pasteboard.co/IHp4HTN.png

Can this be avoided with nvjpegend.

Closing for now. Will re-open once I get nvjpegenc working and the issue is still there.