Zalman, my friends, have a long and rather sky-scraping reputation when it comes to cooling techniques versus noise. Well, the lack of noise to be more precise, or as one of my editors would say, they make 'inaudible products.' The production of noiseless cooling solutions is predominantly why Zalman has become so successful, because hey, PC's are darn noisy these days. We all want to get rid of two things - heat and noise, two annoyances that contradict one another.So we can immediately establish that heat is the most important cause of noise. PC's these days are getting hot and thus we add active fans to cool it down. If you have a new model Pentium 4 processor based on the Prescott core, you pretty much have a heat issue instantly. I have two of these what I like to call 'furnaces' here in the lab and once activated you can honestly fry an egg on them. Seriously. If we look at thermal development over the past couple of years we can see that there is a direct relation between faster and thus hotter products that need hefty fan/heatink combo's and basically a lot of extra cooling in the form of fans in that PC of yours. I've seen modern day PC's with seven fans in them! SEVEN! I swear, add one more fan and the thing should be able to hover. This is a progressively increasing trend and an issue for me personally as all that heat needs to be removed, often by fans and thus that creates a lot of noise.