The myth of dual channel memory

Though the dual-channel computer memory mode has its merits in comparison with the single-channel mode, I am wondering it has been largely misused for marketing purpose because it requires pairs of memory modules.  I have seen people literally believing memory in dual channel mode is 2 times the speed of single channel. The fact is that the former is no more than 10% faster than the later.  Some tests show 5%, and my own test shows a mere 1%.

In contrary to the belief that the dual channel mode allows one channel writing while the other reading, it only allows one channel to prepare for the next operation while the other channel accessing data.  It only saves the preparation time which apparently is no more than 10%, and as low as 1%.  For most computer users, this difference is negligible.