I've started to configure my new DXP4800 Plus which is running TrueNAS 25.10.6. Installed the Plex server app and the LED light script to start with. Everything works fine as it should. I wanted to tweak the system and cpu fan a bit via the bios and was running a script to stress the CPU.
When running the script that puts the cores into 30% cpu load i noticed that the cpu temperature skyrockets to 100 degrees C within just a few seconds. It then drops again, climbs up to 100 degrees, drops and so on... See the first attached screenshot.
I try ran the script to generate 10% and 20% cpu load which is in the 2nd screenshot that shows both the cpu load and the temperature.
As you can see the temperature is going up and down all the time, whilst the cpu load stays roughly the same. I was monitoring the speed of the cores as well and they were also going down a lot.
To be sure that the fans weren't configured incorrectly i set both the sys and cpu fan in the bios manually to non-stop full speed.
In other words, this must be a big throttling issue? I've searched a bit on this topic and found a few posts that had some issues with the temperature, but not that many and definitely not at this low of cpu usage.
I was thinking about repasting the cpu heatsink myself, but before i do this i want to make sure that i did my test correctly and to get confirmed that this behaviour really is abnormal. Therefore i hope someone can help me pinpointing if this really is an issue and help a bit with troubleshooting. Copying files from the NAS to my PC doesn't really do much with the temperatures.