Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects simply to a non-technical, business audience. Over…
Double data rate synchronous dynamic random access memory (DDR SDRAM) is a type of random-access memory module that allows for higher
transfer rates and faster performance compared to earlier RAM modules. DDR
SDRAM transfers memory on both the rising edge and falling edge of a clock
cycle, doubling the transfer rate. This is where the name “double data rate”
DDR SDRAM works on the principle of transferring data on both the rising edge of a clock cycle and the falling edge. While most people might perceive a computer’s clock cycle as a discrete event in time, electronically it is a wave, typically a square wave. This wave has a rising edge and a falling edge. Typical RAM only transmits data on the rising edge, but SDRAM transfers data on the falling edge, which allows it to transfer more data in a clock cycle, doubling the performance of a chip. This is called “double pumping.” DDR can transfer data at a rate of up to 1600 MB/s.
DDR SDRAM modules have complex circuitry to maintain this timing, using phase-locked loops to keep the timing accurate. DDR has been supplanted by DDR2, DDR3 and DDR4. None of these standards are forward or backward compatible, so motherboards with one type of DDR can only use RAM modules that support that standard.
Techopedia’s editorial policy is centered on delivering thoroughly researched, accurate, and unbiased content. We uphold strict sourcing standards, and each page undergoes diligent review by our team of top technology experts and seasoned editors. This process ensures the integrity, relevance, and value of our content for our readers.
Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.
What Does Lurking Mean? Lurking is the reading or viewing of an online community without posting or engaging with the...
Margaret RouseTechnology Expert
What Does Lithium Polymer Battery (LiPo Battery) Mean? A Linux PC is a personal computer that comes pre-installed with the...
What Does Magnetic Disk Mean? A magnetic disk is a storage device that uses a magnetization process to write, rewrite...
Trending NewsLatest GuidesReviewsTerm of the Day