ASUS Prime B550M-A/CSM AMD AM4 (3rd Gen Ryzen) microATX Commercial Motherboard (PCIe 4.0, ECC Memory, 1Gb LAN, HDMI 2.1/D-Sub, 4K@60HZ, TPM, ASUS Control Center Express) - Walmart.com
ASUS ROG STRIX B550-F GAMING AM4 ATX Motherboard - Newegg.com
AMD has decided to block PCIe 4.0 support on all pre-X570 motherboards | PC Gamer
Combination AMD Milan EPYC 7413 +ASUS KRPA-U16 Motherboard with PCIE 4.0,M.2 | eBay
Amazon.com: INLAND 1TB GEN 4 PCIE 4.0 NVMe M.2 2280 SSD +AMD Ryzen 7 5800X Desktop Processor with ASUS TUF X570-PLUS (WI-FI) PCIe 4.0 ATX Gaming Motherboard Bundle : Electronics