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Adamanta 64GB (4x16GB) Server Memory Upgrade Compatible for HP Z440 Workstation DDR4 2133MHz PC4-17000 ECC Registered Chip 2Rx4 CL15 1.2v DRAM RAM at Amazon.com
Crucial 64GB (4 x 16GB) 288-Pin DDR4 SDRAM ECC Registered DDR4 2133 (PC4 17000) Server Memory Model CT4K16G4RFD4213 - Newegg.com