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 512 Mb 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.
DDR3 represents an extension of DRAM's applicability to a far richer multimedia world and wider range of intelligent electronic devices. Paul Fahey, a JEDEC board member and Intel's platform memory operations director, said: “The DDR3 standard will serve as the lynchpin for developing a new generation of memory solutions that address demands for both lower power and high performance. DDR3 will be an essential ingredient in future mobility platforms and those applications requiring the highest performance, such as video-on-demand, encoding and decoding, gaming and 3D visualisation.” These will span the gamut from servers, high-end PCs and workstations to mobile phones and other hand-held devices.
JEDEC is completing publication and release of a range of DDR3-based memory modules, including Registered DIMMs (Dual Inline Memory Module) , Unbuffered DIMMs, SO (Small Outline) DIMMs and other module types and configurations intended for use in desktop, mobile and server computer systems, telecommunications, point of sale and a wide range of other electronic products. Support devices have also been developed and include registers, PLL’s (phase-locked loops) and other interface devices optimised for use with the new technology.
JEDEC is the leading developer of standards for the solid-state industry. Almost 3,100 participants, appointed by some 290 companies, work together in 50 JEDEC committees to meet the needs of every segment of the industry, manufacturers and consumers alike. The publications and standards that they generate are accepted throughout the world. All JEDEC standards are available online, at no charge at www.JEDEC.org.