Indeed, if ASMedia is working on a 4.0 solution, the former would be the worst case scenario. After all the chipset has nothing to do with the 4.0 lanes tied directly tied to the processor. A manufacturer could build a board with a 4xx chipset that has full 4.0 support for at least the first couple PCIe slots (two x8) and a 4.0 x4 NVMe slot, and that's without switches. That being said I'm pretty sure ASMedia is working on 4.0 chipset(s) of some variety, as it wouldn't make sense for them to be working on a new chipset that doesn't at least support a 4.0 link to/from the CPU.As long as the CPU-chipset link is PCIe 4.0 to minimize potential bottlenecks from having PCIe 3.0 downstream links from the chipset to peripherals while still not requiring active chipset cooling, that would be perfectly fine with me. If the chipset feed is still 3.0 though, this might suck since a single 3.0x4 peripheral connected to the chipset can hog all of the link bandwidth.
I think they were referring to asmedia's production of x570 chipsets, AMD is producing their own in-house right now.I might be wrong, but does the article confuse a few things?
"Since ASMedia's PCIe 4.0 tape-out won't be finished until the end of 2019, AMD X570 motherboards might see the light of day until sometime in 2020, perhaps in the first quarter. AMD is in no hurry to roll out X570 motherboards since X570 isn't a replacement for X470."
X570 chipsets will launch on 7/7 in combination with the Ryzen 3xxx series, they won't launch a new processor on an old platform where you can't use some if its key features. There is no ASMedia X570 and AMD X570, it's just X570.