Both! Micron uses the megatransfers per second (MT/s) unit when referring to the transfer rate of the memory. The use of megahertz (MHz) is appropriate when talking about the actual clock speed of the memory. Because all DDR memory technology, including DDR5, is “double data rate,” transfers occur on both the rise and fall of the clock edge. Therefore, the fastest DDR4 memory is measured as 3200MT/s or 1600MHz. While DDR4 transfer rates range from 1866MT/s to 3200MT/s, Micron DDR5 produces 4800MT/s and 5600MT/s rates. All 2024 CPUs (central processing units) will be capable of 6400MT/s.