It's also happening to me but so far only during BF4 and consistently when using Heaven 4.0 with even the mildest overclock.
It's definitely not temp related (aftermarket cooler and mod) but I'm at a loss as to what is causing it. The only thing I can think of is a driver/bios fault...
The ones near the video port are Vrm2.
With the stock heatsink mine were 80c+ (probably because there was no fan above them). With the accelero the fan is directly above which helps a lot. I also used Alpenfohn heatsinks (black) on them which are far better than the Arctic ones
:)