My Ryzen 7 1700 idles at around 30°C. Every 5-10 seconds, it spikes up to 40°C. There are no background processes causing this because it also happens with a fresh Arch Linux installation. Overall CPU usage stays between 3% and 5%, only the temperature spikes up.
I came across several posts on Reddit and Tom's Hardware where other users have the same issue with all Ryzen models, motherboard manufacturers and chipsets. Most answers point out to background processes or "usage of the mouse". Well, my old FX-8350 did not go up 10°C when using the mouse and temperatures only went up when the CPU was under load.
I opened a ticket with ASUS since I thought it had to do with the motherboard / BIOS. They recommended a CMOS reset which I did, but this did not change anything.
As soon as I put a little load on the CPU, these spikes disappear. For example, compiling software on Linux with one thread under full load results in a constant temperature of 36°C without any fluctuations.
The annoying thing about this is that my computer "breathes" due to a custom fan curve of the CPU cooler. Of course I could make a lesser agressive fan curve, but I would rather like to know what causes theses spikes and how to get rid of them. I have read a lot of guessings but no actual explanation so far.
Can anyone help?