What is the best way to "shovel" the 8-pin power supply of the processor?

Question

Iron

There are gaming motherboards with 8-pin processor power. I'm thinking of buying a used one. There are only four pins on the power supply, but there is an extra 6-pin from the video card - the power supply was designed for SLI, but it is not expected at all.
What is the best way to assemble an 8-pin power supply for a processor? What are the adapters?
UPD1. So far there are two options. Or buy an adapter from 4 pins to 8 on Ali, and take the “extra” wires from the second PCI-E. Or, in the same PCI-E, tear off the keys and connect it in addition to the regular 4-pin one.

Answer 1

What about the meaning? It is also important here that the PSU can provide power.
You can safely plug 4x into 8x and everything will work, additional 4x is needed to power the processor during overclocking

Answer 2

некоторые материнки отслеживают наличие 4 пинового или 8 пинового питания, у меня была такая, при 4 пин не включалась, ругалась там на что то, и на монике чернота