Can I put a PCI-E x16 gpu in a PCI-E x16 slot?

No other component can use those lanes except the graphics card Here's an idea that might make it easier for you to grasp what PCI Express

PCIe versions can ABSOLUTELY affect your performance If you've bought a PCIe card and expect it to perform in a PCIe or PCIe slot

does it matter how much you bet on a slot machine Well, it depends on the slot If you install your graphics card in a PCI Express x8 slot instead of an x16 slot, you should experience only minimal performance

does ritual casting use a spell slot Today we answer the question, does your PCIe slot matter? PCIe 16x vs 8x vs 4x TLDR: 6:55