AMD X570 overcomes the greatest shortcoming of the previous-generation X470 "Promontory" chipset - downstream PCIe connectivity. The X570 chipset appears to put out 16 downstream PCI-Express gen 4.0 lanes. Two of these are allocated to two M.2 slots with x4 wiring, each, and the rest as x1 links. From these links, three are put out as x1 slots, one lane drives an ASMedia ASM1143 controller (takes in one gen 3.0 x1 and puts out two 10 Gbps USB 3.x gen 2 ports); one lane driving the board's onboard 1 GbE controller (choices include Killer E2500 or Intel i211-AT or even Realtek 2.5G); and one lane towards an 802.11ax WLAN card such as the Intel "Cyclone Peak." Other southbridge connectivity includes a 6-port SATA 6 Gbps RAID controller, four 5 Gbps USB 3.x gen 1 ports, and four USB 2.0/1.1 ports.
The X570 chipset appears to put out 16 downstream PCI-Express gen 4.0 lanes. Two of these are allocated to two M.2 slots with x4 wiring, each, and the rest as x1 links.
That doesnt make sense. We currently have 32bgps m.2 slots with PCIE3 4x slots. How can it still run 32gbps on 4x slots with PCIE4? it will either be 2x lane m.2 slots, or a 64gbps slot, or the chipset only puts out PCIE3. You cant have a 4.0, 4x slot at 32gbps. The math simply doesnt work.
My understanding is that it takes the pci-e 4.0 lanes and turns them into double the amount of 3.0 lanes. Pretty sure it some sort of magic bean extract that makes it all happen.
Which would make sense for the chipset connected slots, but they also list one slot on a switch with a PCIE4 4x general purpose expansion slot, and the m.2 connected direct to the CPU on some of its lanes is also listed as an old spec 32gbps m.2 connection. So something is fishy about this page.