Thank you, Davcon. I realize that my question was wrong: Orientation means East-West, North-South, of course. Sorry, what I had in mind was a Vertical-Horizontal POSITION. As I have read those copper pipes have inside some inert gas under pressure so it is liquid. When the cooler is standing erect the liquefied gas is at the bottom, contacting the base; heated by the CPU, it turns into hot gas which rises up and is cooled down at the Fin section of the cooler, liquefies and returns by gravity. That´s the normal cycle, now would a horizontal position degrade the coolers performance significantly, or what?. Again, Thanks! jamart821