Arctic Cooling gained widespread respect for their classic VGA Silencer videocard cooler. The cooler helped Arctic Cooling earn a name for themselves as a manufacturer of high performance parts that operated at the threshold of pure silence. With the goal of enforcing that reputation, they've recently released updates to the Silencer line, and have a brand new line of silent cases, and CPU coolers.
In this review I'll take a quick look at one of the new CPU coolers, the P4 Socket 775 part of the Freezer line known as the Freezer 7.
Rated to cool a P4 CPU up to 4.4GHz, the Freezer 7 is physically a very large cooler but surprisingly light-weight. The relatively small base is made of two pieces of copper between which are sandwiched a twin set of heat pipes. The heat pipes can draw up to 200w of heat energy from the CPU and move it to the large array of 40 metal cooling fins which, combined, have a surface area of 5,000 square centimeters.
The 80mm fan is held in place by a patented assembly which Arctic Cooling claims practically eliminates the buzzing noise most 80mm fans typically make. Essentially they've reduced the number of fan supports to the bare minimum in order to reduce any noise created by turbulence as air is forced through the fan. The design does not have any significant protection to prevent stray wires or anything like that from getting tangled in the fan, so extra caution is required there.
I think the cooler base could have used some extra attention as well. It's not as polished and shiny as some other bases I've seen, and there were some minor scratches on it as well. I don't think it would affect performance all that much, but it would certainly help the appeal of the cooler to the average enthusiast who pays attention to those kinds of details.
The cooler itself is held in place on the motherboard by an assembly of 4 push pins identical to those found on standard Intel Socket 775 retail CPU box coolers. To install the cooler you need to push pretty hard on the pins to get them to hold securely which can be pretty hard on the nerves if you don't have the proper motherboard supports on your case to support the new Intel SocketT motherboards.
- Heat Sink: 92 x 72 x 120 mm
- Fan: 77 x 77 x 42 mm
- Overall Dimensions: 92 x 114 x 120 mm
- Rated Fan Speed: 2500 RPM
- Power Consumption: 0.16 Amp
- Air Flow: 36 CFM / 65 m3/h
- Weight: 516 g
- Noise Level: 1.2 Sone
- Thermal Resistance: 0.19°C/Watt
As I mentioned already, at the heart of the Freezer 7 is a twin set of heat pipes whose purpose it is to extract the heat generated by the CPU and whisk it away to the cooling fins.
A heat pipe is essentially a passive heat transfer device with an extremely high effective thermal conductivity. The two-phase heat transfer mechanism results in heat transfer capabilities from one hundred to several thousand times that of an equivalent piece of copper.
A heat pipe in its simplest configuration is a closed, evacuated cylindrical vessel with the internal walls lined with a capillary structure or wick that is saturated with a working fluid. Since the heat pipe is evacuated and then charged with the working fluid prior to being sealed, the internal pressure is set by the vapor pressure of the fluid. This low pressure environment allows the fluid to be vaporized at a much lower temperature than if it were under normal pressure, thus the heat generated by even relatively cool running CPUs is enough to vaporize the fluid (in fact, fluid in a complete vacuum can vaporize at room temperature). Once the fluid is vaporized, it creates a pressure gradient in the pipe which forces the vapor to flow along the pipe to the cooling end of the cooler. The vapor then condenses back to a fluid and gives up its latent heat to the cooling fins. The fluid then travels in the reverse direction back through the heat pipe via capillary action through the wick. Once the liquid reaches the evaporator end it is re-vaporized by the heat of the CPU and the process repeats.
The illustration below should allow for an easier understanding of this process:
A typical heatpipe