Faulty power or what?

http://extreme.outervision.com/index.jsp

go here and put in exact info for you machine with what you've listed for 100% peak utilization you need a minimum 484 watts so even with anything extra you may have you probably would'nt need more than a 600 w

it sounds like an overheating problem to me your ps has Noise Killer Technology During regular operation, the fan slows down to reduce unnecessary noise. which sound to like the ps fan is temp controlled. so as you run 3dmark 06 at the end of the test you cards are overheating and your ps fan is spinning faster because of the increase in temp. you can check this by opening display properties ->settings->advanced-> your card-> and temp setting. run the 3d mark tests except the last one (the one you lock up on)and check the temps. 2 120 mm fans should do well depending on your case. you can also try removing the side of case for better cooling to see if cools any better.

what case do you have?

nice case looks to have good airflow and plenty of room

Well, well that done the trick.. got my first benckmark (8079 with nothing overclocked) so it seems I have poor air flow. Before I was testing and my cards were getting to about 68C, now after running that benchmark (which I have never completed due to freeze/reboot) now is only 50C. A great improvement. The concern I have now is there is nowhere else to mount a fan blowing directly onto those BFG cards.. It amazes me to think of 4 card SLI.. cooling alone stifles me.