I am trying to understand how you decide how big of a power supply to use. You have to power the cpu, ram, motherboard ssd/hd if you use one. Graphics cards and pcie risers. I am confused because I read one person has a rig with 6 graphics card and the system with risers. And there using a 1000 watt power supply. How I ask?. There 6 GTX 1070’s with 150 watts each. The cpu, board and ssd. say 100 watts. Now the pcie risers which I read use somewhere between 40 and 50 watts each. That’s 1300 watts.

What I have is

cpu, motherboard, ram and ssd - 100 watts

7 - MSI GTX 1070 Gaming X - 1050 watts

1 - EVGA GTX 1070 SC - 170 watts

1 - Zotac GTX 1070 AMP Xtreme - 250 watts

9 - pcies ver7 risers - 450 watts

1 - Corsair AX 1200i

1 - Antec Quattro 1000

total - 2020 watts

Was planning on putting 6 cards and the system on the AX 1200i. And the 3 - remaining cards and 9 - pcie risers on the Antec 1000. Is this wrong? Am I wrong with my numbers? I may replace the Zotac GTX 1070 AMP Xtreme because of what it uses in watts 250. With another MSI GTX 1070 Gaming X. One last thing I plan on using Simplemining OS.

Thank you for any help making me understand this.