Random restarts under graphical stress.

[mpsteidle]

I recently aquired a used power supply off ebay (this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16817139051&cm_re=cx_750m-_-17-139-051-_-Product ) for a new SLI setup, i'm about 80% sure this is the reason for the problem i'm having. I was told it only had about 3 months of use on it, is there a way to make sure before I drop more money on a new power supply?

Specs:
-Intel i5 4690k
-Corsair H70 Watercooling
-AsRock Extreme4 mobo
-8gb generic Gskill RAM ( I have used this for a while, and am sure this is not the problem. They are temporary while i wait for my corsair dominator replacements)
-EVGA 650 Ti BOOST
-EVGA 650 Ti BOOST #2
-Intel 730 series SSD 240gb
-Seagate Barracuda HDD 1.5tb
-Windows 8.1

 

[MasterDell]

Extremely likely that is the issue.

 

[computertech82]

Could be the power supply, i can also be something overheating. The bios on the motherboard is designed to shut the system down at certain temps. You could also check the voltages for the power supply there as well.