Following the suggestion in Quick and dirty A64 clocking guide, I ran two instances of Prime95 allocating the affinity of each to a different core. One core was hitting 50% in Task Manager while the other went from 0 to 3% and back to 0. I lowered the overclock thinking maybe one core was handling the OC better than the other, but this time I started one instance, set it to core 0, which ran at 50%, then started the other instance of Prime95 and set that to core 1 and then that jumped to 50%. When I reset my OC back to it's original high, it was ok when done in that fashion, first one to 0 then the other to 1.
Alls well that ends well, I suppose, but my orignal question still stands.
Alls well that ends well, I suppose, but my orignal question still stands.