Is VDDC Current In spike crashing my system?

[GregP]

I'm trying to troubleshoot a problem I'm having with lockups while gaming or running benchmarks. I've got an i5-2500K @ 4.8GHz, 8GB DDR3-1333, two 7970s, and a Sparkle 1000W PS. After a few minutes under load, my screen goes black, fans slow down, sound loops, and I have no choice but to power off my computer and then restart.

I've run a series of tests using GPU-Z and Furmark, and have plotted all the resulting data. My first suspicion was heat, but my tests have shown that there's no particular temperature that causes the lockups -- it can vary from anywhere from 65 to 80.

However, looking at all the voltages, I noticed an odd trend in VDDC Current In, which I presume is the current coming through the 12V lines? In just about all of my tests, my lockup is preceded by a rise in VDDC Current In -- not just a rise, but a steepening of the rate at which it's increasing. It's almost like it's about to skyrocket right before the lockup.

My 12V lines are rated at 18A, but the VDDC Current In numbers right before lockup are anywhere from 20 to 23 ... what's going on here, anyone have an idea? Is my PS flaking out?

Here's the results of 6 tests, with the tests beginning where the numbers jump up, and end with a lockup:

 

[HOODedDutchman]

First thing id try is a different PSU. Or you could try using 1 GPU at a time. Try 1 if no crashes try the other 1, then if no crashes id try a different PSU. 1 less GPU = draw less power. Could be your CPU overclock to. Try bumping voltage up a notch or two. I've had the exact issue before and it was because stress testing my load line calibration would push voltage higher than gaming. So was totally stress test stable, but during gaming id get lockups. Or for a quick check drop your CPU to 4.6 and leave everything else the same. This will tell you very quickly if its your overclock.

 

[GregP]

Thanks for all the suggestions. The graphs above actually show some cases where I used both cards in Crossfire and some where I used just one card. After further testing, I realized that it's only one of my cards that behaves this way. The other, 'good' card does not let VDDC Current In climb when under load, and does not crash my system -- so I think the 'bad' card has some kind of current regulation problem. Time for an RMA.