Crossfire Fury x with non fury x sapphire

[Rafab_21]

I just buy a Fury X and I already had a r9 fury non x sapphire tri-x.
i think my psu is not enough for a crossfire right?. maybe i can let my cpu to 3.5 with 1.2 volts. i dont have any money right now but at the end of the month i will. what psu do you recommend?.
my fury is -72mv and I dont plan on overclocking.
my system specs:
16 gb g. skill
i5 6600k 4.5 1.3volts
msi z170 pro
psu Corsair 800 gs
2 TB 7.2 rpm seagate

 

[renz496]

for a good quality power supply 800w probably should be enough. but corsair GS series is from their low end line up.