AMD X570 vs. X470, X370 Chipset Comparison, Lanes, Specs, & Differences
https://www.youtube.com/watch?v=VvyJikeOXYo
The chipset has 20 PCIe lanes, 16 of which are assignable for IO. Motherboard manufacturers have some limited level of freedom to assign lanes between devices, PCIe slots, SATA or USB high-speed devices, or high-speed networking, depending on goals of the board. 8 of X570’s lanes are always PCIe, the other 8 can be muxed down for things like SATA or those other devices. The X570 chipset also supports 4x USB2.0 ports, 8x USB3.2 Gen2 ports, and two sets of a pick-one choice of either a single use of 4 PCIe Gen4 lanes, dual-device use on a x2 configuration of PCIe Gen4, or 4x SATA 6Gbps lanes. This is going to be where motherboard manufacturers make some decisions to allocate lanes to different slots or ports. Finally, the chipset natively supports 4x SATA III ports, which can be increased by burning one of the pick-one choices on an additional 4 or by using an external controller.
https://www.gamersnexus.net/guides/3482-amd-x570-vs-x470-x370-chipset-comparison