After edit:
...
OK, so using your revised set of numbers, for the same $ purchase, you get 8 S9's, 4 backup control boards, and 1 backup hashboard....
Which gives you 2 rigs on the shelf (to run when your imaginary "16.667% loss" takes place,
twice...)...
So, with the S9 package, we have spare parts for all of the controllers (2 from the shelved rigs
plus the 4 for equal cost), 7 spare hash boards (6 from the shelved rigs), greater power efficiency (enough to buy a 9th rig just from savings, by your own numbers), and someone's still a fanboy?
