In computing, double data rate (DDR) describes a computer bus that transfers data on both the rising and falling edges of the clock signal and hence doubles the memory bandwidth by transferring data twice per clock cycle.[1][2][3] This is also known as double pumped, dual-pumped, and double transition. The term toggle mode is used in the context of NAND flash memory.
DRAM connects to the microprocessor over a parallel bus. In 2015, the present standard is DDR3, a third generation of double-data rate memory bus operating at 1.5 V. Typical motherboards now come with two DDR3 channels so they can simultaneously access two banks of memory modules. DDR4 is ... operating at 1.2V ...