DDR
Double data rate is a type of SDRAM in which data is sent on both the rising and falling edges of clock cycles in a data burst. It is usually referred to as DDR as opposed to DDR SDRAM.

Dual-Channel
DualDDR combines the power of DDR400 with two independent memory controllers, which yields a staggering 6.4GB per second of memory bandwidth¡Xtwice the memory bandwidth of other DDR400 chipsets. Increased memory bandwidth delivers better system and graphics performance, resulting in more overall productivity