The 16GB DDR4 2133 MHz RDIMM Memory Module from HP allows you to upgrade your HP Z400, Z600, and Z800 Workstation's memory. This single registered RAM module features a 16GB capacity, a clock speed of 2133 MHz, a bus speed of PC4-17000, and ECC. Higher RAM lets you experience faster start-up times, run more programs at the same time, and easily toggle between several open programs.