This is a dumb question. But i would like to ask if a high-end graphics card (which requires 2 6-pin connectors) run with only 1 6-pin connector attached?
More aboutshort power
Nope, they might come on, but will cause excessive heating of the components... Leading to burn outs and eventual RMAs.
But if you have the card that requires that much power , I bet it came with a PCIe Power cable that splits one connection into the required type or then fuses two connectors from the PSU to make one properly powered card.
No. Unless power input is detected from both power inputs the card will not run.