Hello, my 5900x with PBO disabled jumps up to 85 degrees when doing simple things like opening program, booting windows, or using programs that use only 1 or 2 cores.
However, when i'm using in full load, (like prime95) i get consistent 65 degress max.
Inconsistency of temperature this is annoying and could posibbly harm cpu life cycle. Also inconsistant change on pwm of auto controlled fans (like cpu) are annoying in confort perspective in home enviroment.
Is there any solution to this without shutting of CBS ?
Sounds like the CPU Fan profile needs to be adjusted to run faster at a certain lower temperature.
It doesn't sound logical that the CPU fan will be cooler at heavy loads or stress than at idle or light loads unless the CPU fan is not running or working correctly (running faster as the processor temperature increases).
Are you using Ryzen Master to monitor your processor's temperatures by any chance?
If not, download and install Ryzen Master and see what temps it shows while idle or light loads and the speeds of the CPU fan.