[SOLVED] Is my CPU overheating and shutting down my desktop?

[Doutor]

I have an RTX 3080 and a Ryzen 7 3700x. My CPU has the stock AMD cooler, so at the time I saved money by not buying one. A few months back my PC was crashing whenever I had long gaming sessions or when rendering 3D objects. At the time I thought it was my PSU because I didn't upgrade it when I upgraded to my 3080, especially when one day after my PC crashed I went to turn it on and nothing happened. Took the PC apart and when I tested my PSU it was dead. So I upgraded my PSU and until last week it was fine, never crashed again when gaming or rendering. So last week I moved and the place I now have my PC is not as cool as the place I had it in before, and when I was gaming the other day the PC just restarted. I found it strange but then I touched my PC case and it was extremely hot, to the point it almost hurt. Decided to leave a game running for a while and check the temps, which my CPU was reaching almost 90ºC. I was going to buy a Corsair H100i water cooler but decided to write this post just to make sure it isn't something else.
So is it an overheating problem with my CPU or could it be something else?

 

[rgd1101]

usually they just throttle itself.
what the full system spec? include brand and model of the psu

 

[Doutor]

usually they just throttle itself.
what the full system spec? include brand and model of the psu

My PSU is a Full Modular Corsair RM850x bought on the 2nd of August so it's pretty much brand new.

Other than that I have a MSI B450 Gaming Pro Carbon Max Wifi motherboard, 16gb of 3600MHz of G.Skill RAM, 2TB HDD and 500GB SSD

 

[Kona45primo]

I'd drop your ram down to stock non docp and see if that fixes your crashing. 3600mhz might be unstable with the 3700x.

Also might want to disable pbo if you have it on, adds a bit to the heat output without much performance.

I've got a deep cool as500 plus on my 3700x and it runs pretty damn cool mid 50's.

 

[geofelt]

Run a temperature monitor like HWmonitor.
Look at the minimum and maximum cpu temperatures.
If your cooler is mounted well and functioning, I would expect to see 10 to 15c. over ambient.
Look at the maximum temperatures. If you are near 95c, then throttling is likely.
That is a good thing, the cpu is protecting itself from permanent damage.

What is the make/model of your case, and what is the fan arrangement.
Any cooler needs a good source of fresh air to let it do it's job.

I would avoid liquid coolers.
If your case permits, A Noctua NH-D15s will cool equally well, be cheaper, quieter, more reliable.
And... they will never leak.