Didnt stop AMD from disabling PCI Express Resizable BAR support, hidden behind AMD marketing wank "smart access memory (TM)" name, on older "chipsets" despite both memory and PCIE controllers being build INTO THE CPU ....

https://www.amd.com/en/technologies/smart-access-memory

Or that time x470 was going to support PCIE 4, but then it was made x570 exclusive