I installed the Dynamix SSD Trim as soon as you mentioned it I tried again with 4GB but it still doesn't look right.
I then used a real file
keeping in mind the read speed of that disk that the iso is stored on is around that number (disk 1), it's a cheap NAS drive
In terms of the power cycle it is probably that I don't keep my machine on at all times, I only use unRAID for 2 gamers 1 pc and do a far few restarts due to software development work.