Some ultra wonky thing is happening to my 990 Pro. Idle temp was 45-50c or so IIRC but since I moved to Win11 from Win10 I've been having issues. I opened Creation Kit game editor to open Skyrim files (just reads) and after some relatively easy work, I saw SSD was reaching 80c and cursor started to stutter a bit. Ambient 21C, it idled at 72C. Heatsink was pretty warm and upon removal I saw an end of SSD was really hot.

There is no case airflow because the system is water cooled and the rads are outside of the case, but this hasn't been an issue before. I check hwinfo and after leaving it open for 20min, it didn't detect abnormal amount of reads or writes. GPU and CPU blocks aren't warm around the SSD. Low power mode in Magician to avoid full power mode did nothing.

I saw Derbauer's video where Thermalright HR-09 2280 got the best results even if top review on Amazon was negative. Maybe just get that?

Then I found that the temps are strongly affected by power plan, but whatever is causing it isn't in control panel settings.

No heatsink idle tests:

Higher performance default settings:71C

High Performance w/ settings identical to Power Saving:71C

Power Saving default settings:61C

Balanced default settings:62C