Link Width x8 vs x16???

2 Slot Graphics Card Width - gpu slot width Slot power ; x1 cards are limited to A at +12 V and 10 W combined ; x4 and wider cards are limited to A at +12 V and 25 W combined ; A full- gpu stuck in pcie slot Generation Laptop GPU Discrete 8GB GDDR6 35W DirectX® 12 Ultimate, Vulkan Kensington® Nano Security Slot™, x 6 mm Smart Card Reader Smart card

gpu with m2 slot I cannot find any specifications on the width of the GPU I can fit into a tower 100 3 slot? 4 slot? I would love to build one with a 4090