In electronic engineering, DDR3 SDRAM or double-data-rate three synchronous dynamic random access memory is a random access memory technology used for high speed storage of the working data of a computer or other digital electronic device.
The primary benefit of DDR3 is the ability to transfer I/O data at eight times the speed of the memory cells it contains, thus enabling faster bus speeds and higher peak throughput than earlier memory technologies. However, there is no corresponding reduction in latency, which is therefore proportionally higher. In addition, the DDR3 standard allows for chip capacities of 512 megabits to 8 gigabits, effectively enabling a maximum memory module size of 16 gigabytes.
According to JEDEC the maximum recommended voltage is 1.575 volts and should be considered the absolute maximum when memory stability is the foremost consideration, such as in servers or other mission critical devices. In addition, JEDEC states that memory modules must withstand up to 1.975 volts before incurring permanent damage, although they are not required to function correctly at that level.
DDR3 modules can transfer data at the effective clock rate of 800–1600 MHz using both rising and falling edges of a 400–800 MHz I/O clock. In comparison, DDR2's current range of effective data transfer rate is 400–800 MHz using a 200–400 MHz I/O clock, and DDR's range is 200–400 MHz based on a 100–200 MHz I/O clock. To date, the graphics card market has been the driver of such bandwidth requirements, where fast data transfer between framebuffers is required.
DDR3 prototypes were announced in early 2005. Products in the form of motherboards are appearing on the market as of mid-2007 based on Intel's P35 "Bearlake" chipset and memory DIMMs at speeds up to DDR3-1600 (PC3-12800). AMD's roadmap indicates their own adoption of DDR3 in 2008.
DDR3 latencies are numerically higher because the clock cycles by which they are measured are shorter; the actual time interval is generally equal to or lower than DDR2 latencies.
GDDR3 memory, having a similar name but being from an entirely dissimilar technology, has been in use for high-end graphic cards by companies such as NVIDIA and ATI Technologies. GDDR3 has sometimes been incorrectly referred to as "DDR3".
Intel Corporation officially introduced the eXtended Memory Profile (XMP) Specification on March 23rd, 2007 to enable enthusiast performance extensions to the traditional JEDEC SPD specifications for DDR3 SDRAM.
|Standard name||Memory clock||Cycle time||I/O Bus clock||Data transfers per second||Module name||Peak transfer rate|
|DDR3-800||100 MHz||10 ns||400 MHz||800 Million||PC3-6400||6400 MB/s|
|DDR3-1066||133 MHz||7.5 ns||533 MHz||1066 Million||PC3-8500||8533 MB/s|
|DDR3-1333||166 MHz||6 ns||667 MHz||1333 Million||PC3-10600||10667 MB/s|
|DDR3-1600||200 MHz||5 ns||800 MHz||1600 Million||PC3-12800||12800 MB/s|
DDR3 SDRAM Module provides 4 GB capacity.(Microsemi Expands DDR3 SDRAM Family with 4GByte Solution for High-reliability Applications)
Nov 15, 2011; Housed in 23 x 32 mm single PBGA package and offered as x64/x72 UDIMM/SODIMM unit, COTS DDR3 SDRAM Device supports data rates of...