Hmmm, if I remember correctly with Ryzen 3000 there was an early badge that had hardware defects that hadn’t anything to do with early AGESA versions like the broken RDRAND, for example.
Does anything in Windows’ Event Viewer show up regarding WHEA?
I haven’t encountered such a unit, can anybody confirm?
I think that’s enough to return it to the shop you bought it from. That shouldn’t really happen at “stock” settings (in quotation because every motherboard manufacturer seems to know better than the chip maker, for some reason).
Have you tried using OCCT or AIDA64 to see if the same happens? It could be that the insane load Prime95 puts on the system make it crash, but it would otherwise work fine in every other application imaginable. What temperatures is reaching at full load?
But still, even after all these questions and tinkering I think that CPU is not working as it should.
I knew the same and some Youtubers that upcycle or fix PCs with older Ryzen 3000 CPUs report seeing many failed ones.
I’ve had way better luck with OCCT on my CPU than Prime95. So if that failed small FFTs it’s done, wouldn’t keep wasting time. Collect all the logs and return it with them attached.
More LLC, as you know, means that you’re pushing and pushing the cores until they all give up. It’s not worth. It should work at a fairly linear LLC.
Today is core two, tommorow it can be any other core or even a complete crap out by the whole CPU.