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AMD's not doing a recall, it works decently enough for most applications. Their response is going to be "if it crashes your application, turn SMT off".

Consider they didn't even do a recall when Phenom had a showstopping TLB bug, they shipped a BIOS patch that disabled TLB entirely.

And remember, Epyc is on a new stepping of the silicon, it's possible this is already fixed on it. (Threadripper is not, however)



> Their response is going to be "if it crashes your application, turn SMT off".

it happens when SMT is disabled

>Epyc is on a new stepping of the silicon, it's possible this is already fixed on it. (Threadripper is not, however)

that's assuming they caught this bug, which i doubt is the case because it's only discovered now rather than being documented in the errata.


I dunno, there were several issues in the SMT implementation publicized earlier, it is entirely possible that the root cause is the same or related.


its possible they overlooked mentioning it in the errata but still fixed it with their stepping. dont give up last hope :)


Epyc crashes quite often, see segfault screen shot.

https://www.reddit.com/r/Amd/comments/6rmq6q/epyc_7551_minin...


TLB, As Translation Lookaside Buffer? Won't memory access slow down dramatically if that is disabled?


Yup, and it did: http://techreport.com/review/13741/phenom-tlb-patch-benchmar...


The Phenom bug was about the L2 TLB; the L1 TLB worked just fine. It still decreased performance significantly — about 5-20 % depending on workload.


As of now, threadripper is epyc silicon with 4 ccx disabled


No! I was going to buy threadripper for this very reason.




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