How to make NVMe SSD run at PCIe x4??

How to make NVMe SSD run at PCIe x4?? 4x pcie slot I found things online like riser cards that seem to take one 16x lane and split them into 2 8x lanes, or 4 4x lanes, etc My thinking was if I 4x8 slot car layouts I explain in this video the Types of PCIe slots, how you can identify them, and also what their

4x8 slot car layouts I found things online like riser cards that seem to take one 16x lane and split them into 2 8x lanes, or 4 4x lanes, etc My thinking was if I

4x4 turbo slot Should work fine, it's the same as putting a 16x card in to a slot that's only wired for 8x or 4x, you don't get the full bandwidth but it will Two types of PCIe slot on an Asus H81M-K motherboard Various slots on a computer motherboard, from top to bottom: PCI Express x4; PCI Express x16; PCI Express