disable XMP, confirm ram settings with CPU-Z and run four instances of HCIMemTest at 250MB or so until %10,000 coverage.
Or 32 rounds of HyperPi 32M test, take ya all day. but its as good.
oh, and yes you should be able to run 1.65v ram with that cpu. really, you can go about as high as you want, like ~1.75v. fear, tho.