8GB Memory Upgrade for HP Workstation Z620 DDR3 PC3-14900 1866 MHz ECC Registered DIMM RAM (PARTS-QUICK BRAND) Capacity: 8GB Form Factor: 240 pin DIMM Speed: PC3-14900R DDR3 1866MHz Halogen Free; ROHS; Warranty: Lifetime FOR SERVERS ONLY. NOT FOR STANDARD DESKTOPS.