The new DDR3 — Double Data Rate 3 — standard, gives a big performance improvement and should reduce power compared with to the DDR1 and DDR2 memory schemes, according to the standards group which made it.
JEDEC, the memory standards association, expects the new standard to be widely adopted. DDR3 is a standard for SDRAM — Synchronous Dynamic Random Access — memory and specifies a 1.5 volt power supply. DDR1 drew 1.8 volts and DDR2 2.5 volts. DDR2 clocked the memory bus at twice the memory cell speed to trade off an increase in memory cell latency against an overall increase in memory throughput. DDR3 clocks the memory bus at four times the memory cell speed to make the same trade-off but this time with a lower power consumption. DDR3 has an 8-bit wide prefetch buffer; DDR2’s is 4 bit; and DDR’s is 2 bit. DDR3 should win out over DDR2 where large amounts of data have to be transferred in and out of memory.
Joe Macri of AMD, the relevant JEDEC group chairman, said: “The DDR3 standard represents the culmination of countless hours of collaboration between memory device, system, component and module producers. This standard will permit emerging systems to achieve greater performance, storage and functionality, consistent with the needs of an increasingly information-intensive world community.”
The DDR3 standard is intended to operate over a performance range from 800 to 1600 MT/s (million transfers per second) and device densities from 512MB to 8GB in monolithic and stacked packages. These could dramatically increase RAM capacities in PCs and mobile phones, better supporting, for example, a move to 64-bit PCs.