Question Why is my CPU temperature 70C only for the first 2 minutes after start-up?

Aug 17, 2022
CPU temperature goes to 70C for about 2 minutes after start-up then back to 25C? Corsair H45 Liquid Cooler. Fans are very loud for the first 2 minutes, then after 2 minutes, the temperature plummets and fans go quiet. during this time I see CPU load go to about 50% at times, and I see large jumps from 55C to 68C then back to 56C and such. Other components are fine, at normal temperatures during startup. During normal operation, temperature hardly goes beyond 40C, even when gaming. Also, I have noticed it only happens for the first start-up of the day, if I turn the PC off and back on again it boots straight to 25C.


Win 11 Master
Jun 12, 2015
Try a clean boot and see if it changes anything - make sure to read instructions and make sure NOT to disable any microsoft services or windows won't load right -

it doesn't delete anything, just stops non microsoft programs running at startup

if clean boot fixes it, it shows its likely a startup program. You should, over a number of startups. restart the programs you stopped to isolate the one that is to blame. Or just leave them not running at all if you don't need them.

Startup is when everything loads so its going to make CPU run hot until its all loaded and it can go back to sleep again. Warmest my CPU get most days is at boot. Its pretty normal.
I'm not sure it's running without any power saving but it's almost certainly less than when full booted, almost certainly with a Ryzen system which manages itself. In the first minutes the OS is running a lot of background activities which takes some time to complete and is exercising the processor rather heavily. And many services only load on a 'delayed start' basis that will extend the time even further. Some of the power management features almost certainly come a bit later on...I've notice my processor only starts dropping to it's lower base clocks after a couple minutes, probably when the custom power plan setting loads up.

Basically the rush is to get the user to a screen fast so they can feel good about fast startups; the other stuff (and there is a lot) can wait a bit.