Im having an issue with my Ryzen 1800x fluctuating in temps every few second with no CPU load. The temp rise and fall is about 8-10C .
I'm running the latest drivers and AGESA. I think I've tried everything from setting a constant voltage on the bios to unplugging blutooth
transmitters as one person posted might be the issue. Here's my current hardware
MSI X370 Xpower Titanium
32GB G.skill ram
Custom water cooling loop with 2 radiators 1 pump
6 Corsair Maglev fans
Here's a link to my Youtube video showing the problem using cam monitoring software.
If anyone has a solution to fix this please chime in.
The issue isn't specific to CAM but seems to be Ryzen related and how it handles low loads. I'm experiencing the same issue, and most people are actually, regardless of monitoring software, even Ryzen Master. Seems Ryzen just doesn't do well with low loads, as beyond 20% it will just be rather stable. For my 1700x it will do roughly the same as you describe (using kraken x62), however while gaming (even with 1-2 loaded threads) it will just lock to something like 42 degrees and stay there. I expect this to be fixed with future OS/Bios updates or even with the next Ryzen refresh.
If you're worried about coolers ramping up and down just set it fixed to something like 50% for most day to day usages and above 75% for heavy loads.
Hope this puts your mind at ease.