3990x tweaking advice!
hi all, ive just finished bolting together my monster new workstation (and first ryzen based system.):
asrock creator trx40
128gb trident z 3200cl15
corsair ax1600i psu.
given the 3990x is the only zen 3 cpu where PBO makes a decent difference, it seemed a shame not to play with it.. however im getting some wierd (i think?) results.
if i let things go totally maxed out, i get 4.15 all core and close to 700w cpu power use.
in my case since im not after records, i set the power limit in PBO to 500w.. cpu draw drops to about 400w and i get a solid all core at 3.9.. which is a decent speedup over stock, without going too crazy on power.
anyway, on to the wierdness.
at full bore, running vraybenchmark, i get banks of cores momentarily downclocking and my scores drop massively.
i assumed at the 500w limit it didnt have that problem, however i note on doing a longer render in max, that it still does it with a 500w limit, just after a few minutes rendering, and not immediately like before.
the wierd thing is, my temperatures are low. my massive custom loop keeps cpu temps below about 65 degrees at all times, my VRMS (not the best on this board i know) stay around 55 degrees, and all other temps in hwmonitor are reasonable. power and current values are all way below limits, and max voltage is about 1.26v.
the only thing i can see that seems connected, is in HW monitor, i get occasional warnings "thermal throttle: HTC" and "thermal throttle: prochot EXT"
note that i also have "thermal throttle: prochot cpu" which never triggers.
also note, this happens a handful of times during a render, but NOT every time my cores downclock.
there is very little online on this subject.. a couple of comments in the hwinfo forum, suggesting that "prochot ext" warning means something other than cpu is overheating.. however i see nothing hot on the sensors. it could apparently also be something erroring out.
any suggestions? id like to get a stable, decent clock speed on my monster.
any advice most appreciated.. not sure what to do!