I am running 5 7950s, Gigabyte WF3 with the f43 undervolted bios and the rig is using 1475 watts at the wall.  I just purchased a kill-a-watt meter and am in disbelief.  I have flashed the f43 bios to the cards, so the voltage of the cards is now 1.09 volts.  That is like 300W per card!!!!!  This seems way to high.  I have read these cards are supposed to be using less than 200W per card.  Any suggestions?