A-Tech 64GB Replacement for HP P05592-B21 - DDR4 2666MHz PC4-21300 ECC Registered RDIMM 2Rx4 1.2V - Single Server Memory RAM Stick (P05592-B21-ATC) at Amazon.com
HPE RAM Memory 1 x 64GB DDR4 SDRAM 64 DDR3 2400 726724-B21 at Amazon.com
64GB (2x32GB) DDR4 ECC Memory Kit - Apple (NZ)
Samsung 64GB, DDR4, 3200MHz, CL22, Single Stick (M393A8G40AB2-CWE)