not enough better using 850 W/1000 W/1200 W.

Let's calculate:
-GPU RX470 has TDP 120 W. RX570 has TDP 120 W, total = 240 W.

-RAM , when used normal condition 2-4 W, when peak power consumption 10 W. Assume take peak power consumption 10 W.

-Processor i7-4790 has TDP 84 W

- SSD has power consumption 4 W (this case, samsung 1 TB when write random activity).

- not yet another parts not calculated.(like 2xUSB RISER ).