The difference between PCIe x1, x4, x8, x16 and x32

x16 slot   Dan x16 slot

List of Motherboards with 4 PCI-Express x16 Slots: ASUS Pro WS TRX50-SAGE WIFI, GIGABYTE A620M C, GIGABYTE B650M C V2, ASUS Prime B760M-A AX, GIGABYTE B760M

It means the card will fit into a single PCIe x16 slot, but the card is as wide as two cards and will take 2 slots at the back of the case  But i didnt unterstand if a PCIe ×8 gpu can be slowed down if its in an PCIe slot Can

slot bca 5000 PCIe cards can always operate in PCIe slots with the same or more lanes than the card For example, an x8 card can operate in a slot with x8, x16, or x32 lanes  A x8 card will work in an x1 slot, but will be limited to x1 speeds A x8 card will also work fine in a x4 slot It will be limited to x4 speeds