Verax Polargate AL S Pentium4 Heatsink Review

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The Verax Polargate AL S can be characterized as a Pentium4 socket 478 heatsink, but compared to just about any other CPU heatsink on the market, it is radically different. For starters, Verax have equipped the Polargate AL S with two of their ultra-quiet CAIRdB fans, back to back. The fans draw air in, and because there is a clear plastic divider between them, the exhaust is directed towards the bottom, or side of the fan where it enters the stacked aluminum fin heatsink.

A couple other insightful thermal design choices come into play, and add up to a nice thermal improvement over past Verax heatsinks, without much sacrifice on the noise front. The downside to all of this innovation is the Polargate's $149USD price tag, through North American distributor VeraxFans.com. There has always been a high premium on low noise cooling, but this may be hard for a lot of mainstream consumers to justify.

Verax's heatsinks have never been the kinds of coolers for overclocking as they focus on noise suppression first, and cooling second. Still, the Polargate Al S does take a few steps towards higher cooling performance which may interest some mainstream consumers.

One thing worth mentioning before we get into this review, is that the Polargate series from Verax is not a one-size-fits-all heatsink. There are separate versions for the Socket 754 AMD Athlon 64 and 939/940 AMD Athlon 64FX processors. Each model comes in a copper or aluminium configuration, so if you are thinking of changing platforms in the near future, keep this in mind.

	Heatsink Specsheet: Model: Polargate Al S HS Material: Aluminum stacked fins Fan: (x2) 1400-3200RPM, 12V, 0.75A Fan Dim: 25x80x80mm (x2) FHS Dimensions: 98x83x110mm Weight: 425 grams Made by: Verax GmbH Sold By: www.veraxfans.com

If this is your first introduction to Verax Ventilatoren GmbH, and their very quiet heatsinks, then perhaps a little background on the company is due. With previous experience in fluid engineering, this German manufacturer produces thermally controlled, essentially zero-noise heatsinks. They have accomplished this by adopting a radically different fan impeller design that reduces many of the noises typically associated with vaneaxial fans. The Verax CAIRdB fan design is unarguably one of the most revolutionary on the market, though it can be a struggle to get acclimated to when moving from traditional cooling systems.

The trend setting impeller on the CAIRdB fan works by accelerating air between its blades evenly, over a substantially longer distance than standard CPU fans. This supposedly keeps turbulent noises down, as the impeller rotates counter-clockwise - totally opposite to that of traditional vaneaxial fans. The CAIRdB fan doesn't move air as quickly as standard fans of the same size, so it is not suitable for overclocking use. To scale the speed of the CAIRdB fan, there is an embedded thermistor located in one of the motor support struts. This thermistor samples the intake air temperature continuously, and lets the fan respond as case temperature with a speed change from 1400RPM - 3200RPM over a temperature range of 20-45 degrees Celsius.

We remain critical of the thermistor placement on the CAIRdB fans, especially when the fans are used on heatsinks as it does not react to the heatsink temperature. In previous Verax heatsink reviews, we gently pop the thermistor out of its cavity and bend it over so it is closer to the actual aluminum fins of the heatsink, for testing purposes. However, since the fans are not located by the metal fins, and the Polargate AL S comes with a DIP switch that controls fan speed, this modification was not necessary.

The DIP switch is attached to a PCI bracket, and allows the user to select from six levels of cooling based on the speed of each fan. For our tests, we concentrated on "ultra cooling" and "super silent cooling" modes which are the quietest, and loudest settings. Printed instructions come with the Polargate AL S which illustrate the different DIP settings available.

Like every Verax heatsink before it, the Polargate AL S makes use of a couple technologies to ensure the most quiet operation possible. The most visible of these are the small rubber posts which separate the fan section from the aluminum fin section.

The rubber posts lock into the fan section and support it a few millimeters above the tips of the aluminum fins. In this respect, any vibrations in the fan are absorbed for the most part instead of being transmitted down and through to the rest of the computer chassis.