Circuit breaker keeps tripping when computer is running.

[nomnompkl]

Hey guys,

I'm running into an odd issue that I can't seem to figure out the root cause other than my computer being on when it happens.

So the main problem is that in my apartment, when I'm playing Diablo 3 (Or any other game really.) the circuit breaker trips and one side of the apartment loses power. I have to reset the breaker every time this happens. This doesn't happen if I am just browsing the web or non-gaming related things.

My initial thoughts was maybe I have a bad power supply, but after some research I suspect I may have an insufficient power supply and it may be drawing more than it can handle. This would cause an arc fault and the safety mechanism in the apartment would trip the breaker to prevent a fire.

Using Newegg's power supply calculator with the below specifications, it recommends that I have a 900w minimum with a 940w recommended PSU. I built this machine using a 750w PSU though because I originally only had 1 of the GTX 480 cards. I eventually added a second one and totally brainfarted about the PSU. The cards run at about 58-60 degree celsius when gaming.

I was wondering besides changing out the video cards to a single GTX 770 (Reducing minimum PSU to 600w) or upgrading the PSU to 1000w minimum, are there any other things I could check? Any thoughts on a surge protector instead of just a power strip?

CPU: i7 960 LGA 1366
Motherboard: ASUS Sabertooth X58
Video Card: 2 GTX 480 running in SLI
Memory: 24GB DDR3 Triple Channel (Brand/Specs escape me at the moment)
Optical Drive: None
Hard Drive: 500 GB 7200 RPM WD.
Other stuff in the case: Corsair H100i, 3 200mm fans, 1 230mm fan.
PSU: Rosewill CAPSTONE Series 750W 80 Plus Gold Certified ATX12V/EPS12V

Any recommendations would be appreciated.

 

[ilal2ielli]

How many amps is the breaker thats tripping?

If you can, unplug or switch the other items plugged into the same breaker to the other side temporarily and see if your system still causes the breaker to trip.

 

[nomnompkl]

I believe the breaker is 20 amps. I'll have to try moving stuff when I get home. Could an overloaded PSU cause this?

 

[Armenius]

It looks like that PSU is being tapped out. My calculations have your system using around 800W under full load. It wouldn't be a bad idea to upgrade to a 1kW PSU to run at 80% load. The GTX 480 has a 250W TDP, which means each one is drawing 21 amps from the +12V rail. Since other things draw power from the +12V rail, you should probably look at a PSU that gives a combined 70-80 amps.

But this will usually only happen if a device is exceeding the current of the breaker. Most breakers in the US are 15 amps, with power outlets drawing 110V/10A. At maximum load a 750W PSU should only be drawing around 7 amps of current from the wall.

Either way, you should upgrade that PSU because exceeding its limits can also damage your computer's components.

 

[rastaban]

I've seen accounts of GTX 480's drawing in excess of 300W each.
Considering the age and inefficiency of Fermi cards, another option would be to make a lateral upgrade to something similar like a GTX 770 and SLI it in the future. This video shows that the 680 is slightly behind 480's in SLI, and since the 770 is a tweaked 680, it is about equivalent to your current setup. Looking forward, GPU's will be more power efficient, so upgrading your PSU now will translate into lower power efficiency in the future (at idle).

Unfortunately, who knows how long 20nm Maxwell is actually delayed by. I'd hazard a guess that the 860 Ti will match the performance of 480's in SLI (outperform 770) while using less than half the power.