Adamanta 128GB (8x16GB) Server Memory Upgrade Compatible for HP Z440 Workstation DDR4 2133MHz PC4-17000 ECC Registered Chip 2Rx4 CL15 1.2v DRAM RAM at Amazon.com
RAM for HP z440 ? - HP Support Community - 7583277
16Gb (2X8Gb) Memory RAM Compatible with Hp/Compaq Workstation Z440 For Servers Only By CMS B7 - Computer Memory Solutions
RAM Update in Workstatino Z440 do not work - HP Support Community - 6881802
64GB (4X16GB) Memory RAM Compatible with HP/Compaq Workstation Z440 SERVER ONLY by CMS B102 - Computer Memory Solutions
A-Tech 32GB Kit (2 x 16GB) for HP Z440 Workstation - DDR4 PC4-21300 2666Mhz ECC Registered RDIMM 2Rx4 - Server Specific Memory Ram (AT378360SRV-X2R2) at Amazon.com
16GB Memory for HP Z440 Workstation DDR4 PC4-17000 2133 MHz RDIMM RAM (MemoryMasters) at Amazon.com