Amazon.com: SHANGZHAOYUAN X99 Dual CPU Motherboard LGA 2011-3 Server Motherboard for Intel i7 5th/6th Gen Xeon E5 V3/V4 Series (E-ATX, 8*DDR4 ECC Max 256G, 2*NVME M.2, 2*Gb LAN, SATA 6Gb/s, PCIe 3.0) :
Early AMD Zen Server CPU and Motherboard Details: Codename 'Naples', 32- cores, Dual Socket Platforms, Q2 2017
Answered: Can I use one CPU in a dual processor motherboard?
Building a Dual-CPU Behemoth from Used Server Parts, ft. CaseLabs & Old Xeons - YouTube
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Amazon.com: ASUS WS C621E Sage Extreme Power Intel® Xeon® Processor Workstation Motherboard for Two-way XEON CPU performance, with U.2, M.2 connectors, dual Gb LAN, USB 3.1 Type-C & Type-A, 10 x SATA