[tryp]

Also, most current DDR3 controllers "scramble" which wire carries which bit based on the address. The idea is that when writing constant repeating data patterns, spreading energy among the wires reduces emitted EMI.

When you do a suspend-to-ram on a current x86 machine, it has to save the "scrambler seed" to CMOS so that it can decode the data it left stored in RAM.

I think this also helps mitigate the attack where the DRAM is chilled to make its contents less volatile, the machine is powered off, and the DRAM is then dumped in search of sensitive material.