Introduction:::...

Having not written an air cooling review for ages, here I am penning my second in a few days. Still, it makes a refreshing break from power supplies I suppose.

I'm not quite sure if the recent surge in CPU coolers is due to some kind of upsurge in air cooling or if it's just one of those unexplainable coincidences that we have to put down to some strange, latent energy force that circles the universe causing all manner of phenomenon. Phenomenon like buses that arrive in threes or friends offering things for sale at ridiculously cheap prices the day after you paid far too much for the same thing elsewhere.

What ever the reason, air cooling seems to be generating interest again, and heat-pipes are this year's must-have accessory. And at that juncture, let's remind ourselves what heat-pipes are all about.

Below is a rather simplified diagram covering the basic principle behind heat-pipe technology. The idea is a fairly simple one. A small amount of liquid, usually water or Ethanol, is sealed inside an airtight tube under a partial vacuum. Heat at one end of the pipe then boils the liquid which, the vapor from which then moves to the cooler end of the pipe, condensing and giving up its heat as it does so.

If the heat-pipe is used in a single orientation then gravity can be used to return the liquid back to the "hot end", but for applications where the pipes are likely to run contrary to the forces of gravity some means of drawing the fluid back to the heat source needs to be employed, and this is loosely known as a wick because it uses the principles of capillary action. Probably the best of the often-used types of wick is the sintered powder wick. Forms of screen mesh, grooved tube walls and porous steel "foams" are also employed, some being better than others, which makes judging heat-pipe efficiency quite difficult. As a vague rule though, short heat-pipes are better than long ones and thicker heat-pipes are better than thinner ones.

Assuming you're still awake, it's time to introduce the two combatants in today's review. The first is from GlacialTech and is a large, rather unusual design with a dual, low-noise fan setup. The second is a hybrid copper and aluminium cooler from the people who recently hit success with the very popular and award-winning Kamikaze HSF, Scythe.

Both coolers sport heat pipes, but is that where the similarities end? First let's take a closer look at them....