How to Make libvpx "VP9 Encoder" Faster with simultaneous video encoding

Context

libvpx is very slow when encoding especially with only one video file This is because libvpx is a a big part of the problom is because libvpx is bad at multi threading.

The solution

Is to run multiable separate video encoding jobs at the same time one for each core, this causes only a very small decrease in fps per video but all combined it equates to a much higher total fps than just running one encoder job at a time on my 4c4t i5-6660t cpu it gets a 65% frame rate boost when tuning 4 simultaneous encoding jobs at cpu-used 3 which makes it around the same speed as H.265's Slow Preset

Simple way of encoding multiple videos at a time

I put one video file in each 4 separate folders and have it encode in 4 separate terminals (you could also use tmux) there's probably a better way of doing this with scripts though, then i use ffmpeg for encoding it with this line here

ffmpeg -i test.mp4 -c:v libvpx-vp9 -pass 1 -quality good -threads 1 -lag-in-frames 25 -crf 32 -b:v 0 -cpu-used 3 -auto-alt-ref 1 -arnr-maxframes 7 -arnr-strength 3 -aq-mode 0 -enable-tpl 1 -row-mt 0 -f null -
ffmpeg -i test.mp4 -c:v libvpx-vp9 -pass 2 -quality good -threads 1  -lag-in-frames 25 -crf 32 -b:v 0 -cpu-used 3 -auto-alt-ref 1 -arnr-maxframes 7 -arnr-strength 3 -aq-mode 0 -enable-tpl 1 -row-mt 0 output.webm