Quote Originally Posted by jgree32 View Post
... so decided to try 1.65V Northbridge......Result is one smoked northbridge.

Not good. I've been running my P5B for a while now at a bios setting of 1.65 volts without any issues. Temps measured with an IR thermometer at idle or load aren't bad either. My NB heatsink was originally making poor contact so I pulled it off, cleaned it, squared it up and replaced it with AS5. The heatpipe was preventing it from sitting flat on the chip so I had to bend it a little. It sounds like the heatsink was making poor contact on your board as well.