Windows 10: Question Unexplained software crashes

Hello everybody,
I recently built a new computer (specs below) and randomly, softwares crashes.
For instance, some days I can play for hours without any trouble and another day the game will crash like 4 times in an hour.
It happens mostly while playing (crash happens on several games) but also while browsing on Chrome.
When it happens, the soft I'm using just crash without any error message.
Sometimes in the event observer I got an ID 1000 and sometimes nothing is reported in the event observer.
I already reset my computer thinking it was an issue with the windows registry but nothing changed.
A also ran memtestx86 in order to test my ram and no error occured.
I'm hoping someone might know a way to fix it or at least what's causing it.
My specs :
AMD ryzen 1920 X
msi X399 SLI
GeForce 2080 RTX
G.Skill 2x8GB DDR4 3200MHz
2 Samsung SSD 860 EVO 2.5" (500 Go)
Seasonic 750W Gold

:)

 

all games crash!

I suggest you run rthdribl > http://www.daionet.gr.jp/~masa/archives/rthdribl_1_2.zip
Increase the window size step by step and watch your vga temps permanently.
What happens?
If it crashes, run at stock speeds as suggested before and retry.

P.S.: When your system locks, does the display signal turn off after a time?
Stuttering sound or no sound at all when freezing?
What X1800XT model do you own exactly?

 

Overclocking / Undervolting guide for Vega 56 or 64?

Here's a quick laundry list:

List of software to use for overclocking and testing
Examples:
Wattman (and how to find and use it, like an overview, including profiles)
Unigine Valley or Heaven (use this for quick testing while changing settings in Wattman and checking for stability / artifacts) ...just suggesting this
How to monitor cores / mem speeds and temps during testing (I've seen screen overlays, and others using GPUz)

Step-by step overclocking in Wattman
Fan speeds
Power limit
Temp limit
Voltages
Core speeds
Memory speeds

 

Unexplained crashing

I wasn't quite sure what I should now be doing to solve the problem. Eight days on and the PC keeps crashing.

Any suggestions gratefully received. Thank you.