Yes, this is what I was asking about. Is there a 90% rule?
It's 80% for reasons of long (way before crypto was a glint in Satoshi's eye) painful experience. There are tons of examples of "not quite enough" PSUs (especially see the older Goldshell Doge Mini burnt connector issues) being bad news.
LeftLane10Under replied to your earlier PSU post and provided a bit of clarity on temps and hash rate about 4 posts above.
Specifically:
I don’t recommend running these at max settings. I don’t live in a cold climate and these got really hot fast! 75C and the room was hot. I went from 12.5th/s in turbo @ 800watts to 14.5th/s at 1050watts for 4 units (two 750w psus). Each unit saw about 266wats at full speed.