RAM Update in Workstatino Z440 do not work - HP Support Community - 6881802
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
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