(SDRAM) memory, which uses a clock to synchronize the input and output of signals. This clock is coordinated with the CPU clock, so the timings of all the components are synchronized. SDRAM also implements two memory banks on each module, which essentially doubles the memory throughput; it also allows multiple memory requests to be pending at once. A variation on SDRAM, called double-data rate SDRAM (DDR SDRAM) is able to read data on both the rising and falling edges of the clock, which doubles the data rate of the memory chip.
