look for Specific Expertise dual cpu mainboard am4 look for grain impact
AM4 TITANIUM Motherboard AM4 Socket - AMD Ryzen 1/2/3 Gen CPU DDR4 RAM HDMI VGA | eBay
Early AMD Zen Server CPU and Motherboard Details: Codename 'Naples', 32-cores, Dual Socket Platforms, Q2 2017
ASUS TUF Gaming B550-PLUS AM4 ATX Motherboard TUF GAMING
MSI B550M-A PRO Motherboard (AMD Ryzen 3000 3rd Gen AM4, DDR4, M.2, USB 3.2 Gen 1, HDMI, Micro ATX)
Amazon.com: SHANGZHAOYUAN X99 Dual CPU Motherboard LGA 2011-3 Server Motherboard (E-ATX, 8*DDR4 ECC Max 256G, 2*NVME M.2, 2*Gb LAN, SATA 6Gbit/s, PCIe 3.0) Support Intel i7 5th/6th Gen Xeon E5 V3/V4 Series :
So I found a site claiming the existence of a dual cpu motherboard with am4 socket compatible with threadripper pro. Is it true? Can you put 2 ryzen CPUs in it? Link
ASRock > X300TM-ITX
24 Cores, 48 Threads for $360: Dual-X99 Jingsha Motherboard vs. AMD R9 3900X - YouTube