Sure, its possible to look up what one's CPU consumes, but there are
several hardware and software components drawing power, and it quickly
becomes difficult to know how much is really being consumed.

I'm particularly interested in the consumption of a lighlty equipped
PentiumPro machine which is on all the time, no monitor. It is
passively cooled, and the heatsink feels quite cool to the touch, so i
am hoping it is below the 50W mark.

I also have a P4 1.8GHz machine with 2 HDDs and a 21" CRT, I'm curious
to find out how much it really consumes, and how it compares to the
value from manufacturer's specs.

Herminio