Now I feel sorry for going off on a tangent on this thread…, maybe a mod can be more effective in forking the thread into a separate one about PCIe hotplugging.
I think that’s what PRSNT#1 and PRSNT#2 are meant to help with, that is to help electrically isolate the card until it’s actually sitting in the slot, but you’re right, should work != does work. And the fact there’s ways to do slow start, doesn’t mean cards or motherboards actually have all the circuitry on them.
I wonder if saphire or msi can confirm/deny doing any even if minimal testing of these scenarios, regardless of whether it is or isn’t a supported use case for the products in an actual production device, just out of curiosity.
Also, pcie slots provide both 12V and 3v3 on various pins, 12V is a lot in a box full of semiconductors, even if you could switch those powerlines on/off with software and that part is working, or if you had a physical clicky power switch that would disconnect those pins, it doesn’t mean that you will always be able to do so, and doesn’t mean that something won’t die if you try to unplug / plug back in a card in a live system… it’s definitely not a typical use case, lots can go wrong.