Question

What is the difference between SDRAM and DDR-SDRAM

Answer 1

DDR is faster than SDRAM because it operates on double the data

Answer 2

SDRAM (synchronous dynamic ram) completes one operation per clock cycle. DDR-SDRAM (double data rate synchronous dynamic ram) completes two operations per clock cycle. DDR is effectively able to process double the data than single data rate RAM (double the bandwidth) within the same period.