[Anemone]

Remember too, that for many the degree of improvement has changed. This was touched on earlier in the comments about just how much cpu power is "needed" these days. 5-10 years ago the difference in power between a low run of the mill machine and a top powered one, was power that some folks really used.

What I find is that it's really the classic, how much money and effort for how much improvement formula at work. Years ago many of you saw this coming. If I have a heatsink with a reasonably quiet fan that comes within 5-10C of the same performance, and within 200mhz of oc'ing performance of the watercooled system, what then is the return for spending on the watercooling system? Most folks are not going to notice much in 200mhz, and frankly silicon can stand 5c and often 10c higher temps for years without any real concerns as long as it falls within spec. That tends to make for a next to zero return, for more money and more effort. That's nice if there is something that really gives you satisfaction in building the thing, or watching it run, or perhaps the additional silence it provides, but most folks aren't going to bother.

Air cooling only needs to come to 90% of the ability of water cooling and then cost, effort to install, and performance return on the cpu take over. And don't compare a poor air cooling system to a well designed water cooling system. Apply equal amounts of design to both and you'll find that the pinnacle of each is extremely close in performance. The case and airflow, noise and fan choice, all come into play, but when equal amounts of good thought are put into both kinds of designs and maximized for your choice of performance or noise, things can come pretty close. And close is fine, because many of us are edging out all they can from a cpu. But cost does come into it. Spend $200-300 on a cooling system, when in a year or two that same money will buy you a cpu that is vastly faster than the increase you got out of the current cpu? The math, the very "need" for that extra few mhz of performance, just don't support a broader market acceptance. All this at a time when laptops are the largest growing sector of the pc market. People want quiet, surely, but they want smaller, more portable, the whole "chic factor" more. And if the laptop market is an example, they are happily willing to pay more and give up performance at the same time! Funny as it seems even high end air cooling feels the pain. Let alone a market where the costs are at least double air cooling.

Sorry this got too long. But I think you all will see the idea here. The market for this sort of thing isn't nobody. There are enthusiasts aplenty. But the broad applicability for the technology has run into the other competitive choices and a degree of improvement factor, that are making things very difficult for water cooling.