好吧
wikipedia,intel等大公司正等著你去改寫

Dual Channel-enabled memory controllers utilize two 64-bit data channels, resulting in a total bandwidth of 128 bits, to move data from RAM to the CPU.

In computing, a computer bus operating with double data rate transfers data on both the rising and falling edges of the clock signal
摘自wikipedia...

原文 http://en.wikipedia.org/wiki/Dual_channel
http://en.wikipedia.org/wiki/Double_data_rate