Adobe Media Encoder (Why is it not using all the available power) System Spec:
16 core 3950x
Nvidia rtx 3080
64gb of ram
1tb nvme
2tb ssd
4tb hdd

Software
AfterEffects - v17.5.1 (build 47)
MediaEncoder - v14.7 (build 17)

Problem:
So I'm outputting a fairly complex render at 1080p 30fps and the media encoder is only using 3% of the CPU and 6% of the GPU. I have always had issues with rendering but this new pc I have just bought should be rendering much faster than the old setup but they are basically identical. Can someone explain if there is something I can do to increase the performance or explain why the hell this shit is like this?
So after quite some time it turns out ame is pretty useless on using as much comp resources as you have. I did how ever find a really solid solution. Rendergarden is a third party tool that splits the output render into chunks and renders them all in parallel. I went from using no more than 3% cpu to render garden using as much as I asked ie 96%.
This axes render times by a factor I genuinely cannot believe. In real terms it cut a 3h 52min render into a 24min job. (16 CORES SMASHES THROUGH RENDERS)
It does cost money but if you are experiencing this issue this 100% removes the media encoder render bottleneck.