https://wccftech.com/asus-z490-motherboards-tested-intel-rocket-lake-desktop-cpu-lack-pcie-gen-4-0-support/

Back in July, we reported how ASUS was severely lacking PCIe Gen 4.0 support on its Z490 lineup of motherboards, a highlight feature of the Intel Rocket Lake Desktop CPUs. Fast forward to 2021 and we can finally confirm this as our sources have got the chance to test out several ASUS Z490 boards with a Rocket Lake CPU.

You can definitely get some more insight on ASUS's dire situation in this detailed post but in short, ASUS missed out big on the PCIe Gen 4.0 bandwagon with its Z490 motherboard lineup whereas all other major AIBs implemented proper Gen 4.0 support on their Z490 motherboards. Our source got their hands on several ASUS Z490 motherboards and tested them with Intel's Rocket Lake CPU. The motherboards include: