Old news to me, but maybe very new to others.
The current being put through a module of RAM can also dictate how high you can clock your RAM or in same cases no difference at all. Depends on luck(unknown factor) and what chips are used.
D9 series chip are particularly vulnerable and is the cause of 680i burning up RAM on stock vDIMM(1.8V)
Under DFI boards the option for it is oftenly refered to "Drive Strength" with two selections 'High' and 'Low'.
So if your RAM is running above average temperature (by touch) at stock settings, see if there's an unusual option that doesn't relate to timings on RAM. If not.... change your mobo to a DFI?