DaveW wrote:

Wrong. The "Northwood" P4's do NOT automatically throttle when overheating.

That's going to come as one hell of a surprise to the Intel folks who wrote
the specs.

The problem, which I also ran into, is that you probably have the Hyper
Threading turned ON and so the CPU is being overtaxed by doing heavy duty
video work with only half the CPU's cycles. The other half is being used
for your other running processes. And 79 C for a P4 will GREATLY reduce its
life.
I would recommend getting a better CPU cooling unit AND turning off
HyperThreading if you plan on doing much DVD encoding.