Re: Antminer S9 Volt Rocket Ship firmware mod! ~Time to Max Out Your Bitmain PSU~
18.4 TH?? 
You can push to the same with this firmware you might just get some hw errors and I do not recommend. Going over 18th generally means 2kw of power draw.
It works with Antminer S9i 14TH/s or old S9?
It will work on both of them. I might compile a firmware setup for the apw3 aka 1600w psu vs the new 1800w psu.