DDR2-SDRAM is high-performance
main memory. Over its predecessor,
DDR-SDRAM, DDR2-SDRAM offers greater bandwidth and density in a smaller package along with a reduction in power
consumption. In addition DDR2-SDRAM offers new features and functions that enable higher a
clock rate and
data rate operations of 400
MHz, 533 MHz, 667 MHz, and above. DDR2 transfers 64
bits of data twice every
clock cycle. DDR2-SDRAM memory is not compatible with current DDR-SDRAM
memory slots.
See also DDR-SDRAM.