Divide them by 4, and get 1200W HP Platinum rated server power supplies dead cheap and happy mine 
. For around 60-80$ including breaker board and cables is no brainer, pico board lets round it to 90$ for a Platinum rated server grade power supply. Forget about evga,seasonic etc.
1200 watt power pack can't power the whole cards, OP said he has 7x 3070 and 4x 3080, that's over 1300 watts for the cards alone minus the motherboard power draw, 2000 watt power pack will do the job better or even 2400 watts . For around 60-80$ including breaker board and cables is no brainer, pico board lets round it to 90$ for a Platinum rated server grade power supply. Forget about evga,seasonic etc.