PSU cannot provide enough power

I've semi-recently built a new Linux rig for A/V editing and the occasional gaming. On some games I've experienced consistent reboots with high graphics settings that, I believe, are due to PSU overloading and its protection kicking in. Even at maximum load, the PSU should be well enough to feed the system.

cases where I didn't have problems:
OpenArena @ max settings, 5760x1080
QuakeLive @ max settings, 5760x1080
Serious Sam 3 @ max settings, 1080p (5760x1080 works for a while, then goes back to 1080p)
All valve games @ max settings, 1080p
Trackmania (via wine) @ max settings, 1080p
All 2D games
GPU accelerated video encoding/playing, flash
General 3-monitor PC usage

fail cases:
SpectraBall @ anything above lowest setting/resolution
Tiny and Big @ anything above lowest setting/resolution
Bitcoin mining on GPU
Probably more...

I've spent time tweaking game settings and reading high and wide across the net about this and it all points to PSU overloading. Strangely enough there are cases which are more graphic intensive than some of the fail cases - I don't know what to

(relevant) PC specs
FSP 650W (600W/50A +12V rail)
Gigabyte GTX 660ti (150W TDP)
i5 3570k (77W TDP)
3x 7200rpm HDDs
All USB devices connected via the powered hubs on the displays

The VC is powered via two 6-pin connectors that are on a single 12V rail

misc
Just before the reboots, CPU and GPU temperatures are well in their respective limits, no error logs and system isn't at full load.
Nvidia proprietary drivers 310.44
Ubuntu 13.04

Unfortunately I haven't bought a Win7 copy yet (*nix user, I've never got into games till now) and can't test it under Windows.

question
How to track down the actual problem. What component fails? What should I do to remedy this?

additional questions
1. Is there any point in trying swapping the two 6-pin conenctors to the VC, or trying the molex-to-6-pin cables that came with the VC?
2. Is this a VC power overdraw or PSU overload?
3. Is this constant testing (intentionally causing reboots) bad for the hardware
4. Can this be a problem in the drivers?
5. Any way to measure what power is actually drawn from the PSU, the 12V rail and the VC?

Thanks in advance!

Alexander Ivanov

Posted 2013-05-22T12:07:26.997

Reputation: 171

You are barking up the wrong tree; PSU overload => shutdown, not reboot. – psusi – 2013-05-22T13:22:56.040

The whole system powers off and after a few seconds it powers on again. I think I have 'boot after power outage' enabled in the BIOS, and the MB does exactly this when the PSU recovers. – Alexander Ivanov – 2013-05-22T13:31:00.620

Answers

I tested the whole configuration with a 500W PSU and it was enough to withstand full load on the VC and CPU. The Problem is a faulty PSU not that 650W aren't enough.

Alexander Ivanov

Posted 2013-05-22T12:07:26.997

Reputation: 171

From the graphics card's website: Power requirement 450W

You need a beefier power supply. While a lot of things don't cause your issue, the actual GPU isn't likely "loaded" like it would be when you do benchmarking or bitcoin mining (both of which will max the GPU's utilization).

Nathan C

Posted 2013-05-22T12:07:26.997

Reputation: 2 522

How is my PSU not good enough? It's 650W, and those 450W take into account other components in the box - it is not the actual power draw. – Alexander Ivanov – 2013-05-22T12:41:51.587

650W is decent for mid-level cards, but the card you have is considered "high end" and I'd recommend no less than a 1000W power supply. If it's your PSU, then this furmark test will also cause a reboot: http://geeks3d.com/gputest/

– Nathan C – 2013-05-22T12:44:32.830

@AlexanderIvanov - The card requires 450W but you also have the processor and 3 hdds that require power. Your problem normally is caused by not having enough system power. I disagree with Nathan's comment of course about 650W being decent for only mid-level cards. I do suggest running the Fumark test of course. – Ramhound – 2013-05-22T13:06:31.060

1Nonsense. The card isn't going to draw more than 200W tops. 3 hard drives? ~24W. That CPU and motherboard? Max ~100W. I have a similar setup with a good 550W supply and it never draws much more than 200W. It isn't the total wattage you need to watch out for, but how much current it can supply on each rail. Cheaper supplies have two 12v rails and the second one goes to the video card and is typically weaker. – psusi – 2013-05-22T13:30:47.150

While I consider this PSU a budget one, it wasn't the exact definition of cheap. By specifications and reviews around the web, the PSU has a single +12V rail that does provide 50A of power (600W). I've just installed the FurMark on my rig and when I return from work I will run a couple of tests. – Alexander Ivanov – 2013-05-22T13:36:13.780

Did the GPU tests - PC restarts the moment I run any of them. On one of the reboots my BIOS complained: 'Power supply surges detected during the previous power on' – Alexander Ivanov – 2013-05-24T15:33:01.737

That's definitely pointing to a failing/inadequate power supply. – Nathan C – 2013-05-24T15:34:04.630