After testing installing on a HDD and experiencing the 4 hr initial wait time on first run(Compared to the 2 hrs i had to wait on my SSD(yes you try to do something, it locks up, and you wait 2 hrs,Unfreezes after a little while, Compiles a bunch of assests while still seeming frozen, after a while you will get a progress bar in the bottom right on how many shaders it needs to compile)), i would suggest running this purely from a SSD due to the amount of information trying to be read and dealt with.
I run the ADK off a HDD (WD BLUE 1TB) and have never had to wait anywhere near those times for startup or compile, yes i will admit there is some long loading times but only about 30-45 mins at most.i don’t have a monster computer only running i5 2400 12Gig MEM and 1060ti grafix.