[wtallis]

> benefit from memory running in DDR mode (2 sticks).

That's not what DDR means. DDR means transferring data on both the rising edge and falling edge of the clock signal. That's true no matter how many chips or modules are involved.

You're thinking of running memory in a dual-channel configuration, which requires two modules but is not synonymous with using two memory sticks, because using both channels also requires putting your two memory modules in the correct slots so that you don't have two modules sharing one channel.