Vega 64 - Odd Temperature Pattern/Graph

[EXCellR8]

I recently picked up another Vega 64 reference card second hand so I could resume gaming @ 4K while my main PC goes down for upgrades. Card works fine but I did notice something peculiar that doesn't occur with the other Vega 64. Upon looking at the temperature/usage graphs in AB it appears that there are this sudden 'spikes' in temperature that occur over and over again. The overall temperature curve seems 'fuzzier' than it should be?

Could there be a problem with the sensor or perhaps the card itself? My other reference Vega 64 doesn't do this (I would have for certain noticed it) so I'm considering doing a BIOS flash. The card seems to perform fine but this just seems odd. Has anyone seen anything similar or had a similar reading with another card? Both of my Vega cards are Sapphire reference models, but the one in question is the air cooled limited edition; I don't believe they are different otherwise.

 

[Stuka87]

What kind of load is it under? Can you detach the afterburner graphs so that we can use usage and clockspeed along with temperature? We should see some sort of correlation there.

 

[EXCellR8]

Will do, I've been meaning to compare Superposition Benches anyway.

Looks fairly normal to me aside from the odd spikes in memory temperature during a full load operation, which I can't really explain outside of an anomaly. What's sort of interesting to me is that the overall temperature curve of the memory doesn't have the fuzziness like the GPU core. You can see this just by looking at the first two lines being stacked right on top of each other.

 

[DrMrLordX]

Use something like GPU-z to do a graph of HBM hotspot temps. See if those correspond to the memtemp spikes.

 

[EXCellR8]

Sorry for not following up on this before. Here is the GPU-Z graph after about 5 minutes of gaming:

Ran AB again just to compare

Same sort of "fuzzy" temp curve but nothing seems to be that out of whack; the card does perform well overall. I did notice however that, on a couple of occasions, the card seemed to get 'stuck' at half utilization--which resulted in quite a framerate drop. Could be a driver or Windows bug I suppose but I'd never encountered anything like that on my other Vega 64.

I may try to update from VGA BIOS 8737 to 8892 but I doubt that'd make much a difference.