Thanks for the details Achim

I have not had those weird noises on any board yet with Phenoms BTW.

I am running 2700/2800/2700/2800 stock voltage stable nearly 20 hours now ...
Benched 2800/2900/2800/2800 stock volts too.
Looks like I'm making headway, one core is most likely weak but the rest strong -- that's the one that causes a freeze at the 10-18 hour mark. Trying to figure out which one.
Next setting will be 2800/2800/2700/2800 and you know why...