Crucial 32GB Kit (16GBx2) DDR4-2133 MT/S (PC4-2133) CL15 dual ranked x4based ECC Registered Server Memory CT2K16G4RFD4213 More speed. More bandwidth. More efficient Reduced power consumption @ 1.2V For networking, cloud computing, HPC, Big Data and more and speed is 2133 MT/S Check for system compatibility using memory selector tool @ crucial.com Your system may support multiple memory configurations based on the density, quantity and type of memory modules installed. Please consult the documentation for your specific system & remember Registered & Unbuffered memory cannot be mixed / Load Reduced DIMM's cannot be mixed with standard Registered DIMM's