Pc restarts in the middle of "demanding" tasks, new hardware installed.

[Memoryes]

I recently bought a 1080Ti and installed it, while playing some more demanding titles my pc restarts

Psu - 750W Cieftec
Motherboard - Z370p D3 Gigabyte
Ram - 16gb 2x8 Vengeance DDR4 3000Mhz

Cpu - i7-8700k Lga 1161 3,7 ghz

Gpu - Geforce Gtx 1080 Ti Gaming OC 11gb Gigabyte
Bios f10

OS - windows 7 64-bit

 

searched internet for answers, so far ive tried 

Reinstalling the gpu

reinstalling drivers

deleting all gpu drivers and then doing a clean install

installed new Bios

clean gpu driver install after updating Bios

re-installing motherboard drivers

 

before the restarts all my temps are under 70c

ive played assassins creed odyssey after the gpu install, works fine for 10minute-ish and restarts the pc on its own
tried to open gta v benchmark and pc restarts before it even starts

 

[Memoryes]

operating system is windows 7 64-bit, forgot to write ._.

[Fasauceome]

Does it bluescreen or just go into regular windows shutdown?

[homeap5]

Something may be wrong with GPU. Try to underclock it using MSI Afterburner. If that helps - replace GPU.

[Memoryes]

Doesnt blue screen, screen goes black and the pc starts up again,
ill try to figure out how afterburner works

[homeap5]

Set Core Clock to -200, Memory Clock to -200 - then Apply.

I had once Gigabyte GPU that has blackscreen problems. That was years ago but the same problem. I don't trust that brand after I saw how their few motherboards works and how that old GPU works. Everything but Gigabyte.

 

You may also increase Power Limit (in Afterburner) to the max.

 

But if it resolves your problems with black screen - replace card. It's not a solution. It should work out of the box on default clocks.

[Memoryes]

tried -200 core clock and -200 mem clock, pc restarted the same way as earlier

[homeap5]

Well, try underclock to the max and increase power limit to the max.

But I'm afraid that is GPU anyway.

 

[Memoryes]

underclocked -500 and pc didnt crash, does this mean the gpu is broken? ;-;

[homeap5]

Is not working like it should work.

So I think yes - it's broken. You made workaround but it will not last long.

 

[Memoryes]

ok, thank you for your time and help. u,u

[Memoryes]

Ok, it seemed like a psu problem to me from the beginning but i tought "meh, it has enough watts in there" but then i started thinking about how old the thing is and yeah im not gonna ramble on forever

old psu, switched to another one, everything works great now.

 

thank you for all the help and time tho everyone who helped.