Generations DDR (DDR1) was superseded by DDR2 SDRAM, which had modifications for a higher clock frequency and again doubled throughput, but operates on the same principle as DDR. Competing with DDR2 was Rambus XDR DRAM. DDR2 dominated due to cost and support factors. DDR2 was in turn superseded by DDR3 SDRAM, which offered higher performance for increased bus speeds and new features. DDR3 has been superseded by DDR4 SDRAM, which was first produced in 2011 and whose standards were still in flux (2012) with significant architectural changes.
Generations DDR (DDR1) was superseded by DDR2 SDRAM, which had modifications for a higher clock frequency and again doubled throughput, but operates on the same principle as DDR. Competing with DDR2 was Rambus XDR DRAM. DDR2 dominated due to cost and support factors. DDR2 was in turn superseded by DDR3 SDRAM, which offered higher performance for increased bus speeds and new features. DDR3 has been superseded by DDR4 SDRAM, which was first produced in 2011 and whose standards were still in flux (2012) with significant architectural changes