The AMD X570 will be the first consumer chipset to support PCIe 4.0, offering double the bandwidth compared to the previous generation and therefore reducing the risks of bottle neckings.
A new leak suggests that not only will the chipset feature PCIe 4.0 but it will have 40 lanes to use which is a huge jump up from the 28 PCIe of the previous generation.
In comparison, Intel X390 has just 24 lanes, Intel x299 has between 52 and 68, while AMD x399 has 64.
The PCIe leak was part of the reported Ryzen 3000 clock speeds yesterday. A lot of the lanes are used for various functions on the motherboard. The X570 supposedly allocates 8 lanes for USB 3.1 Gen 2 (10Gbps) and four for USB 2.0 with up to 12 for SATA.
With the popularity of NVMe drives, and the large bandwidth of USB 3.1 Gen 2 it makes sense for additional lanes to be added into the enthusiast chipset. For example on my old B350 motherboard, adding an NVMe drive disabled 2 SATA ports.
I am also hoping that with more lanes, we might see more companies offering 10Gbe ethernet ports, either via addons or built into the motherboard. Not that there are any affordable switches yet.