The DDR2-RAM, and DDR2-SDRAMs, is the second generation of DDR-RAM (Double Data Rate Random Access Memory), a further development of SD-RAM. A laptop SD-RAM called is a SO-DIMM (Small Outline Dual Inline Memory Module) mounted with memory chips, which organizes itself and synchronized with the system clock of the processor. The synchronous operation speeds up and simplifies the access of the processor to the main memory, whereby information can be retrieved quickly. In addition, the module can thus be adapted to any application. DDR2-RAMs differ mechanically and electrically from their predecessors. The required operating voltage for example, could be reduced from 2.4 volts to 1.8 volts. In addition, the signal quality has been improved, and thus the system stability. The so called prefetching more data is read in advance from the memory itself is being accessed over four memory banks. So The internal memory provides four bits instead of 2 bits per clock step. There are DDR2-RAMs with different memory chips that provide an increasingly better bandwidth. Among these RAMs 400, 533er, 667er, 800er and 1066er memory chips. The bandwidth of DDR2-RAM is 3.2 GB/s to 8.5 Gb/s.
There are different types of DDR2-RAM, for desktop PCs, servers and laptops, which differ in particular by their physical size and the number of contacts. Laptop DDR2-RAM usually have an edge length of 2.5 '' to 3 '' and includes 200 contact pins. They are available in our shop in the memory sizes 256MB, 512MB, 1GB and 2GB.