The Spirit of Morpheus
Hello,

By End August 2021, I had purchased a new EVGA RTX 3080 Ti FTW3 Ultra Gaming from a German retail Hardware-Shop. However, I couldn't insert/use my new-bought EVGA GPU for over a quarter year because around the same time, my motherboard (ASUS Maximus XI Hero, Z390) suddenly died for no apparent reason and it took that said quarter year waiting game of sending it (the motherboard) to ASUS, then ASUS rejecting RMA (an absolute d***-move!!) and then finally buying a used examplar of the same motherboard in January 2022 - and shortly afterwards (End January 2022), I could finally insert and start operating my then-new EVGA RTX 3080 Ti. Immediately after insertion, I installed the then-latest Nvidia driver for Windows 7 (472.12 WHQL) and then flashed the latest firmware/vBIOS via Precision X1 software.

In the first months, everything was fine, because I almost exclusively played very old games (Q3A-Engine based games from the early 2000's) during that time period, which didn't really tax my GPU at all (very light load).

Then, however, I started playing newer games (from March 2022 onwards) that quite caused real GPU load and Battlefield 4 was the first game where this event occured: everytime I entered the player customization/loadout menu during a multiplayer session, just after a couple of seconds, my entire computer suddenly shut off - at the same moment/second, when the screen went suddenly black in front of me, I could hear the fans firing up to full-speed VERY LOUD for a moment - though, I couldn't exactly pinpoint, whether it was the GPU's fans or if it was my Seasonic PSU's fans or both. And immediately (within 1-2 seconds) after shutdown, the PC automatically started up again with literally zero error messages - no POST or BIOS error messages and also no Windows error messages (except the pre-boot notification before reaching Windows desktop, that my system wasn't shut down properly the last time...).

And this phenomenon also occured in almost every newer game that I played during that time: Crysis 3, Deus Ex: Mankind Divided and the original Crysis (from 2007, not the Remaster - but with my own custom ExtremeQuality config that is extremely stressing both the GPU and particularly the CPU because of the exceptionally high polycount). The only exception from this was Battlefield 3: no matter how long I played or where in the game/menus I was, there was no sudden emergency shutoff not even a single time. Crysis (2007), on the other hand, caused this phenomenon to occur particularly rapidly (but not instantly like BF4 Loadout Menu); usually within 30 minutes of starting the game.

For all games, the FrameRateLimiter was set to 120fps at maximum either ingame or in Nvidia Inspector software, but in some cases (Crysis 2007) I set it to just 60fps.

Then, in July 2022, I had the idea to undervolt (but NOT underclock) my RTX 3080 Ti in order to fix this problem - and indeed! It seemed to be solved: no more sudden shutoffs during high-load gameplays!

...until about 1-2 months ago, when the exact same problem started re-occur again. Moreover, now even very old games (the Q3A-Engine based games mentioned above) cause the exact same phenomenon: sudden emergency shutoff followed by immediate automatic restart of the computer! And it gets worse: from now on, neither undervolting and even additionally underclocking (fixing GPU clock around 1,8 GHz in V/F-Editor, reducing memory clock from OC'ed 10000 MHz to 9000 MHz - that's 500 MHz below the default clock!) my 3080 Ti do not solve this problem anymore!

And I'm finally out of options (ideas) now...

My PSU is a Seasonic Prime TX-850 (850W, 80 PLUS Titanium, Single Rail) purchased new just a few months before my EVGA RTX 3080 Ti.
 
Looking forward for any help, support or advise...

T.S.O.M.

Sajin
Could be either the psu or gpu. Best thing to do would be to test the gpu in another known good working system.