JoshRox24 :
Dunlop0078 :
Did it do this with both psu's? Now I have never heard of senty power supplies and that is never a good thing, it is very cheap for a 750watt unit so im guessing it is of very low quality and it could be the cause of your problem. Check event viewer in the system log and see if an error was recorded when your system alarm went off.
i never tried the other psu, the wattage was too low for the gpus requirements
and here is the psu im using right now http://www.amazon.com/Sentey%C2%AE-Power-Supply-750w-Bronze/dp/B00I3NUDVC
Then Im going to have to blame this on the psu. Your psu is 60 dollars this is how much a good 750watt unit costs:
http://www.amazon.com/EVGA-SuperNOVA-Crossfire-Warranty-220-G2-0750-XR/dp/B00IKDETOW
You would have been much better off just getting a decent 550watt unit which you could get for around 60 bucks so if there is anyway you can get your money back for that psu I would, then buy an xfx 550 or something.
What 350watt psu do you have you may be better off running that, 350watts should be enough for a 960 if its a decent psu.