Why is PMS speed < 1 when the CPU is seriously underutilized?

Plex Media Server Desktops & Laptops
,
14

It’s a pretty simple shell script.

mkvmerge -o temp.mkv -M -S --no-global-tags --disable-track-statistics-tags "$1"
if [ $? -ne 0 ]; then
  echo `date` Bad file: Error \($?\) \"$1\" >> $Logfile
  rm -f temp.mkv
else
  echo `date` "Keeping: " "$1" 
   mkvpropedit -s title= temp.mkv
   mkvpropedit --edit track:a1 --set language=eng --edit track:v1 --set language=eng temp.mkv
   mkvpropedit --edit track:a1 -s name= temp.mkv
fi