Upgrade the memory in your HP Z420, 440, 640, and 840 workstations using the 8GB DDR4 2133 MHz RDIMM Memory Module (Promo) from HP. This single RAM module features an 8GB capacity, a clock speed of 2133 MHz, a bus speed of PC4-17000, and a 288-pin RDIMM form factor. Adding more registered RAM to your workstation lets you experience faster start-up times, run more programs at the same time, and easily toggle between several open programs. By offering Error Checking and Correcting technology, this RAM will help your workstation encounter fewer errors that can corrupt data sets and introduce system issues. This RAM is protected by a limited 1-year warranty.