PC restart immediately during heavy gpu usage

[uncle_joseph]

My desktop was working well for the past 4 months, but several days ago I had this problem, it keeps restarting when I play video games or during gpu stress test. This happened when I play video games that put heavy load to my gpu for like 10 minutes, but later it's getting worse, my PC restarted suddenly when I run stress test using Furmark.

Here's my spec:
Intel Core i5 4690k
MSI Z97 Gaming 5
XFX Radeon HD 7850 2GB
RAM 8GB, 2 x 2GB 1333Mhz plus 4GB 1600 Mhz
Corsair VS550
Windows 8.1 64 bit

I tried to narrow down the problem, such as:

■ Reseating the graphic card and switching to another PCI-E slot■ Rolling back the driver to the previous version■ Downclocking to factory setting■Putting my graphic card on another PC■ Removing RAM one by one■ Check for virus and another malware

All of those things lead to the suspicion that my PSU might be the problem, so I tried to replace it with another PSU of same type, but then my PC refuse to start and I can't even see BIOS screen. So I put my PSU back and unplugged one of my HDD, then I repeat to stress test my GPU, strangely it didn't restart, so I thought I've had the culprit, an HDD with voltage problem.

Today, my PC restarted suddenly while I was browsing the internet, and when I tried to stress test the GPU, it keeps restarting again within seconds, even after I reset the OS to factory setting using the installation DVD. A faulty HDD was not the problem, the PSU is still the prime suspect

Then I stumbled on this thread and give it a shot, magically it hasn't restarted since last GPU stress test for about 10 minutes with high performance power plan.

Can someone enlighten me with what's wrong with my PC, because I don't think that the thread I mentioned above can be a permanent solution for my problem.

Sorry for the long post, and thanks in advance.

 

[Zerk2012]

Corsair VS550
That is a very low quality power supply and probably the problem.

 

[uncle_joseph]

Corsair VS550
That is a very low quality power supply and probably the problem.

Could you recommend which series is good for this manufacturer?

Meanwhile I'll still hold this thread open to gather as much info as I can before I decided to buy another PSU

 

[Zerk2012]

Corsair manufactures no power supplies never has and never will, their all rebrands and the good ones are overpriced.
If it's running OK now changing the power settings then let it go.

 

[uncle_joseph]

I will try to put different GPU and PSU, if PSU is the real problem I might replace it with another. Could you recommend which brand is good?

*update*
I forgot to mention that i tried to replace the GPU with a lower spec one, HD 5570, it comes without 6 pin PCI-E plug. When I tried to stress test the GPU it doesn't restart, could this really a PSU problem?

 

[Zerk2012]

Corsair VS550
That is a very low quality power supply and probably the problem.
The 5570 uses a lot less power.
Seasonic, XFX to just name a few good ones.

 

[uncle_joseph]

*update*

Definitely PSU problem, got it replaced with my friend's and tried the steps I mentioned before, no restart happened as for today.
Went to a computer store for replacement, the store owner said that Corsair VS series is so bad that he won't even recommend it to anyone who shops there.

Thanks for your help Zerk.