Random freezes cpu spike

[Swiebertjeee]

So basically this kind of came out of nowhere, since my system was running fine and stable for a really long time. So basically starting yesterday evening I got a random crash as in freeze where I just had to kill the computer (I was browsing Ikea website for baby stuff which shouldnt be demanding on the pc) but I was like eh whatever. So I continued my shopping spree and went to sleep. 

 

So basically today I came back from the office, and I thought you know what I launch up some game and relax , I'm done for the day (cpu intensive game). So I get into the game no issues and the moment the action begins the pc froze for a few seconds and then see bottom half of my screen black and other top half screen nothing and the pc reboots. That got me thinking, what could possibly be the issue? So I tried to look at events logs and tried to look on google for good methods to test it (crashed during reading some forum) and found nothing else than 'unexpected recovery from shutdown'. So I managed to open task manager see the cpu @ 100% and the screen freezes (no reboot). So basically I was like okay I need to test my cpu so I want to use cinebench for that. 

 

So I open hw monitor for monitoring and press start and boom freeze (no reboot) , which made me think why did it do that? on the freeze screen I don't see any heat or big cpu increase right of the bat. 

 

 

So after this I was like, okay let me try that again and see if I see the same result. So i boot up again and I get this message on startup: 

 

and it reboots short after. 

 

Then I boot up again run cinebench no problems without issue and I was like okay I need help. I am writing this now. 


So basically it started yesterday, the only thing that I can imagine that has to do anything with it is that I removed my gpu yesterday after work, and later placed it back in. On booting then my computer said new cpu installed, I was like huh what so I rebooted pc and it was normal again so I was like okay whatever weird. Could it be that I touched anything in the process which may have caused this alert and perhaps the issues I am having? 

 

cpu specs: 

i5 8600k (over clocked like 8 months ago has been stable ever since) 

RTX 3060TI Gigabyte OC , I think I have it for about 2 months, never had issues. Not overclocked, stock settings

z370 asus mobo 

650W PSU (evga nova series)

 

 

So can someone help me find out what my issues is, and how to correctly find out what the issue is?

 

Edit: Kept this open while reading my daughter a story for 10 mins when I came back I saw my computer rebooted.