DDR memory offers twice the data bandwidth of conventional PC100 or PC133 SDRAM, and is particularly well suited for high-performance servers and workstations, which need optimal CPU-memory performance. Double Data Rate (DDR) SDRAM is precisely what the name implies. A clock cycle can be represented as a square wave, with the rising edge defined as the transition from "0" to "1", and the falling edge as "1" to "0". In SDRAM, only one of these wave edges is used, but DDR SDRAM references both, effectively doubling the rate of data transmission.