GeeCoolGuest
GeeCoolThe PRO 9975WX has only one choice: WRX90 on sTR5 with eight-channel DDR5 ECC RDIMM. The purchasing essentials: CPU/BIOS support list, memory QVL, and 350W-class power delivery with VRM cooling.
Pick expansion by need — PCIe 5.0 slots, M.2/U.2, networking, and management ports. TRX50 or consumer boards don't match the socket, so there's no cheaper workaround.