This is a simple comparison table of SDR, DDR, DDR2, DDR3 and DDR4. With the introduction of each generation, the data rate increases, improving system performance. The voltage, interface and the package type are different with each generation. Therefore, a redesign is required when migrating designs from one generation to another, including the PCB layout. However there are processors that support multiple interfaces. The JEDEC committee set the standards for the SDRAM interface to make it easier for users.