Posted by Silvia,
The DDR RAM memory or double-data-rate synchronous dynamic random access memory, offers greater bandwidth than ordinary SDRAM. It is a type of memory-integrated circuit used in computers that transfers data on both the rising and falling edges of the clock signal. Highly efficient, it nearly doubles the transfer rate, while maintaining the frequency of the front side bus. For example, if data is transferred 8 bytes at a time the DDR RAM transfer rate could be calculated as (memory bus clock rate) × 2 (for dual rate) × 8 (number of bytes transferred). This means with a bus frequency of 100 MHz, DDR-SDRAM gives a maximum transfer rate of 1600 MB/s. DDR Memory has 184 pins and one notch. The DDR operates at a voltage of 2.5V. The DDR SDRAM package sizes and the standards of speed have been set by JEDEC (Joint Electron Device Engineering Council). There are two sets of specifications: one for memory chips and the other for memory modules.