I will answer with your terms.
full x16 riser are used to build farms on two types of video cards 470, 480, and 4 GB analogs for mining Ethereum using a lol miner and 3060 so that the Ethereum hash rate does not decrease.
Otherwise, you can use regular x1 raisers. This does not affect the hashrate in any way.
for your video card, be sure to use 6 pin raisers, for example
https://www.aliexpress.com/item/1005002082548102.html?do not use sata raisers
Why are full x16 riser need for 470/480 cards? PCI-E 1x work fine from my experience, is there something that running them in a 16x helps with?