A-Tech 32GB Kit (2 x 16GB) for HP Z640 Workstation - DDR4 PC4-21300 2666Mhz ECC Registered RDIMM 2Rx4 - Server Specific Memory Ram (AT378361SRV-X2R1) at Amazon.com
Amazon.com: HP Z640 Tower - 2X Intel Xeon E5-2680 V3 2.5GHz 12 Core - 128GB DDR4 RAM - LSI 9217 4i4e SAS SATA Raid Card - 2TB (2X New 1TB SSD Enterprise) -
REVIEW: HP Z640 Workstation - AEC Magazine
HP Z640 Workstation 1.90GHz Xeon E5-2609V3 4GB DDR4 Ram 256GB SSD W7 P
HP Z640 Workstation
HP Z640 Workstation Single Processor Configure To Order
HP Z640 - Refurbished Workstation | PC Server & Parts
Adamanta Micron Original 128GB (4x32GB) Server Memory Upgrade for HP Z640 Workstation with Single and Dual CPU DDR4 2400MHZ PC4-19200 ECC Registered Chip 2Rx4 CL17 1.2v RAM at Amazon.com
A-Tech 32GB Module for HP Z640 Workstation - DDR4 PC4-21300 2666Mhz ECC Load Reduced LRDIMM 2Rx4 - Server Specific Memory Ram (AT378361SRV-X1L1) at Amazon.com
Second CPU Riser for HP Z640 Workstation with 1x 1.70GHz Xeon E5-2609V