Look up: DDR-RAM

1. 
   DDR SDRAM
   Double Data Rate SDRAM can theoretically improve RAM speed to at least 200 MHz. It activates output on both the rising and falling edge of the system clock rather than on just the rising edge, potentially doubling output. This is expected to be the next predominant type of PC memory.
   Found on http://www.mcsx.co.uk/glossary.php
   
   
2. 
   DDR SDRAM
   `DDR SDRAM` or `double data rate synchronous dynamic random access memory` is a class of memory integrated circuit used in computers. It achieves greater bandwidth than the preceding single data rate SDRAM by transferring data on the rising and falling edges of the clock signal (double pumped). Effectively, it doubles the transfer rate without increasing the frequency of the memory bus. With data being transferred 64 bits at a time, DDR SDRAM g...
   Found on http://en.wikipedia.org/wiki/DDR_SDRAM
   
   
3. 
   DDR-RAM
   Double Data Rate Random Access Memory
   Found on
   
   
4. 
   DDR-SDRAM
   Double Data Rate-SDRAM
   Found on http://www.geocities.com/ikind_babel/bab
   
   
5. 
   DDR-SDRAM
   Double Data Rate Random Access Memory
   Found on
   
   
6. 
   DDR2 SDRAM
   In electronic engineering, `DDR2 SDRAM` or `double-data-rate two 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. It is a part of the SDRAM (synchronous dynamic random access memory) family of technologies, which is one of many DRAM (dynamic random access memory) implementations, and is an evolutionary improvement over...
   Found on http://en.wikipedia.org/wiki/DDR2_SDRAM
   
   
7. 
   DDR3 SDRAM
   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 devices. It is a part of the SDRAM family of technologies, which is one of many DRAM (dynamic random access memory) implementations, and is an evolutionary improvement over its predecessor, DDR2 SDRAM. Its prima...
   Found on http://en.wikipedia.org/wiki/DDR3_SDRAM