Older system randomly shuting down

[poly_salama]

My old PC started shutting down (it's like some unplugged it from the wall) at semi random times and then it tries to start up again but it can't. It just loops without getting event to the boot screen until i unplug it from the wall, then it can start up normally. This happens at semi random times. Sometimes when i'm browsing the web, watching a movie or just typing. Weird thing is some games cause it to shut down immediately (like rocket league), but when i run synthetic tests for cpu and gpu (furmark, prime95) at the same time it doesn't shut down. I've also noticed that it much more stable under linux, i rarely experience any shutdowns. My first thought was the PSU but if it was the problem the pc should shut down under synthetic test. Any thoughts?

 

Gigabyte EP43-UD3L

Q9550 @3.4Ghz

Geil 8Gb DDR2

Radeon 6950

Samsung 840 EVO

Random HDD

Seasonic G-550

[ScratchCat]

Synthetic tests generally do not cover varying loads particularly well, a PSU might be able to provide enough power constantly but a suddenly changing load such as opening a game or website will cause the voltage to drop under a threshold causing the PC to crash.

[poly_salama]

Are there any Synthetic tests that would cause sudden load changes so that i can test it?

[EsaT]

Most parts of that are starting to get old so something could have certainly worn.

Are there any errors in event Viewer?

 

On 5/30/2018 at 4:33 PM, ScratchCat said:

Synthetic tests generally do not cover varying loads particularly well, a PSU might be able to provide enough power constantly but a suddenly changing load such as opening a game or website will cause the voltage to drop under a threshold causing the PC to crash.

Then again starting synthetic "power virus" test would cause harder power draw change than games.

Unlike nowadays drivers of those graphics cards didn't auto-throttle pre-emtptively when detecting Furmark:

Gaming peak 128W, Furmark max 182W

https://www.techpowerup.com/reviews/HIS/Radeon_HD_6950/27.html

[ScratchCat]

8 hours ago, poly_salama said:

Are there any Synthetic tests that would cause sudden load changes so that i can test it?

Not that I know of however you could use the Windows High Performance energy plan to limit the minimum frequency which should reduce great changes in voltage.

As it crashes with web browsing you could use a script to open a website every 20 seconds or so to see if it only crashes at certain points. Example script:

import webbrowser, time

while True:
	webbrowser.open("linustechtips.com") 	#open this link
	time.sleep(15)	#wait 15 seconds

 

The Linux issue seems strange, are you testing with synthetics on Linux to?

6 hours ago, EsaT said:

Then again starting synthetic "power virus" test would cause harder power draw change than games.

Unlike nowadays drivers of those graphics cards didn't auto-throttle pre-emtptively when detecting Furmark:

Gaming peak 128W, Furmark max 182W

https://www.techpowerup.com/reviews/HIS/Radeon_HD_6950/27.html

That depends on if the CPU returns to idle immediately or remains in a higher state, additionally Intel CPUs increase voltage and lower clock speed when running AVX e.g. with prime95 v29+.