Most ASUS Z490 motherboards lacking necessary PCIe 4.0 features?

Last month we saw the launch of Intel's Z490 chipset. This platform supports the Comet Lake-S processor with its LGA1200 socket and will also support the upcoming Rocket Lake-S. The latter is rumored to arrive later this year or in early 2020. Rocket Lake-S will deliver PCI Express 4.0 on the Intel desktop platform but it seems not all currently available Z490 motherboards have what it take to support PCI Express 4.0.

In a new article, WCCF Tech writes that motherboards from ASUS will not be able to support PCI Express 4.0 as they lack the necessary hardware implementation, whereas boards from MSI, ASRock, and Gigabyte do mostly have these features:

So coming to the conclusive evidence provided by the forum member, we get to look at the PCB of several motherboards from MSI, ASUS, Gigabyte, and ASRock. You can see in the images below for several Z490 boards that aside from ASUS, almost every other motherboard manufacturer has got PCIe Gen 4 support right. As for ASUS, only its top two motherboards, the ROG Maximus XII Hero & the ROG Maximus XII Extreme retain the necessary requirements to get PCIe Gen 4.0 to work.

To get PCI Express 4.0 to work, motherboards need a PCIe 4.0 slot, a PCIe 4.0 M.2 slot for SSDs, and a PCIe 4.0 clock generator. A PCI 4.0 re-driver is optional to enhance the PCIe 4.0 signal and a PCIe 4.0 switch is also optional, to switch the Gen4 signal. Based on the WCCF Tech article, it looks like only two ASUS motherboards will be able to support PCIe 4.0.