plex media server on android

I have an Anewish® M8S+ Plus Android 5.1 TV Box 2G/8G Amlogic S812 Quad Core 4K 1000M that I am not doing anything with. I would like to make it into a media server. As you can see it only has 2gb of memory. My plan is to attach a 5tb external HDD to the box either by

  1. Using it as removal storage
    or
  2. adding it as device storage so the memory goes from 2gb to 5tb

A have a few questions

  1. which of above the would work better for a media server?