Few know this, but Intel/AMD CPUs released in the last few years support transparent full memory encryption, where the RAM content is encrypted with a random key kept in the CPU memory controller and generated at reset.
It's typically disabled in BIOS, since it has a small memory performance penalty (0.1%->1%)
It's typically disabled in BIOS, since it has a small memory performance penalty (0.1%->1%)
But it would completely prevent this attack.