Thanks for the response. Just wanted to give a quick update. Since removing all unnecessary software like Ryzen Master and MSI Dragon Center and doing another BIOS update and CMOS reset I couldn't reproduce this strange temperature readings again. Even after hours of logging, temperatures seem...
So I guess it's very unlikely that benchmark software could have such an effect on temperature readings and fan speeds? Thats just what I was afraid of.
I detected a problem with a pretty new system based on a Ryzen 5 3600 and B450 Tomahawk Max. When gaming I logged sensor readings with HWinfo and while on game I saw that the CPU fan was not spinning up anymore. Instead it was around its lowest RPM of about 300 constantly. This absolutely didn't...