I call fighting with fermi a frustrating process. Went thru another dewar tonight trying to solve the mystery, just finished with nothing good to report. A dewar a day keeps Kal away.
My ES 980x has no cold bug with HT off, first time I've ever run without HT and took it down to -196c. Decided to see what the best clock I could get and managed a 6150mhz @ 1.88 vCore before chalking it up till the next session.

and for Fermi