Another quick post before we call it a night, a couple of diagrams are circulating around the web that claim to show the AMD X390 and X399 chipset diagrams. There's not a whole lot information, the info was discovered by a Reddit user and it's not clear if this is the real deal or a mockup created by sometime with too much free time.
The leak shows a X390-based motherboard layout from ASUS, an X390 block diagram and a X399 block diagram. The X390 diagram seems to show a "Ryzen 2700" processor while the X399 diagram shows a dual-socket with two Ryzen 4700 CPUs.
Two chipset block diagrams were also posted. The X399 chipset for dual-CPU motherboard and X390 for single-CPU motherboard. The first diagram could be a new workstation/server platform for Naples CPUs, as we can see it has ECC memory support. Meanwhile, X390 corresponds to earlier rumors about Ryzen HEDT, which is meant for 16-core 32-thread Ryzen processors. Also unlike X399, the X390 has PCI-E lanes connected directly to the chipset.
So if those diagrams are real, then X390 chipset would support up to 44 PCI-Express lanes.
Full details and two more images can be seen at VideoCardz. As noted before, I would take this with a grain of salt.