8GB Memory for HP Workstation Z440, Z640, Z840 DDR4 PC4-17000 ECC RDIMM RAM | eBay
X2D67UT#ABA -- HP Workstation Z440 - MT - 4U - 1 x Xeon E5-1620V4 / 3.5 GHz - RAM 8 GB - SSD 256 GB - HP - ZaynTek
HP Z440 Workstation 4x4K Multi Monitors CPU 3.5GHz RAM 32GB SSD 512GB Win10 P600 [751489-006] - $819.00 : Professional Multi Monitor Workstations, Graphics Card Experts
16GB Memory for HP Z440 Workstation DDR4 PC4-17000 2133 MHz RDIMM RAM (MemoryMasters) - Walmart.com