5gigs on stock is not only extreme, it's ing ludicrous. Starting with quality of equipment: The heatsink is designed to handle mainstream computing; running at stock temps for stock performance.

You will, invariably have to up voltages and multipliers, ultimately pushing more electricity through the CPU. As you reach the maximum cooling capacity of the heatsink unit, you begin to run the risk of seriously damaging your processor.

That sort of high end overclocking really can not be done with stock equipment. Even with my equipment, I can get a suicide run of 4.2 on my 955be.

As the man before me said, "Keep us posted." I'd love to see the results of this.