Rentay at a guess you have LLC set at 100%. In this case when you heavy load the system CPU voltages actually increse slightly.

Sergio VRM on 350 ??? what setting is that??? I have the rest of the settings dialed in for a fully stable 5.0ghz 2600K. Maybe with 350 vrm I coudl lower CPU voltage a touch???

I have to turn off HT on BF3 also running 3 x 580 GTX in Tri Sli and latest drivers, most running multiple cards have to for some reason.