Asus PRO B550M CCSM Desktop Motherboard AMD B550 Chipset Socket AM4 Micro ATX 128 GB DDR4 SDRAM Maximum RAM DIMM UDIMM 4 x Memory Slots Gigabit Ethernet HDMI DisplayPort 4 x SATA
OWC 64GB (4 x 16GB) PC21300 DDR4 2666MHz 260pin SO-DIMMs Memory Ram Module Compatible with Mac Mini 2018, iMac 2019 and up, and Compatible PCs (OWC2666DDR4S64S) at Amazon.com
Crucial Technology 64GB (4X 16GB) 288-Pin RDIMM DDR4 (PC4-21300) Memory Module Kit, CL=19, Registered, 2666 MT/S Speed, ECC, 1.2V, 2048Meg x 72, Dual Ranked, x4 Based at Amazon.com
V-Color 32GB (2 x 16GB) ECC SO-DIMM DDR4 2666MHz (PC4-21300) for NAS Micro Server/Workstation/Compatible with Synology 21 Series 2Rx8 CL19 1.2V (TES416G26D819K-VKC) at Amazon.com