JMC 401100 Phoenix 70 Radial Fin P4 Heatsink Review

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It's always kind of interesting to receive a prototype heatsink for testing, especially when it comes with a full set of blueprints explaining how the whole thing is put together. The Phoenix 70 (model No. 401100) is a new heatsink from JMC Products that might remind more than a few of you of the old Arcticooler from Agilent Technologies. That heatsink has been wiped from the corporate slate, but its memory lives on in the form of JMC Phoenix 70 which even has a little Arcticooler logo on it.

The original Agilent heatsink was made for socket 370 Pentium III processors, but this version is intended for use with socket 478 Pentium 4's or Socket 603/604 Xeons. The unit we tested was configured for socket 478.

What makes the JMC Phoenix 70 so interesting is that the heatsink fins are cut from a single block of aluminum in a radial 360 degree pattern. The 67mm diameter fan impeller is mounted inside a ring of thin fins and when the heatsink is in operation two separate air flow streams are created. The first stream consists of air as it is sucked into the fan through fins at the top of the heatsink. The second stream is created as exhaust air is pushed out through the fins at the base of the heatsink.

Unlike a host of Taiwanese heatsinks which use similar techniques now, or in the past, this is not simply an extruded heatsink which has been machined to flat ninety degree angles below the fan, fins extend all the way to the base of the fan motor. The internal geometry of the Phoenix 70 has the fins at a slight angle which helps provide a non-turbulent airflow that creates very minimal noise. This is not to say the heatsink is silent, but is does have its own very unique low frequency sound signature of about 53dB in amplitude.

	Heatsink Specsheet: Model: Phoenix 70, 401100 HS Material: machined aluminum Fan: 5500RPM, 12V, 0.21A Fan Dim: 25x67x67mm FHS Dimensions: 52x75x83mm Weight: 389 grams Made by: JMC Products Sold By: www.jmcproducts.com

As JMC tend to be a high volume manufacturer things are kept quite simple on this cooler - there is no copper or heatpipe insert in the base, though such additions could produce very interesting results if they are ever added in the future.

The basic construction consists of the main finned heatsink inserted into an aluminum base which is suited for standard socket 478 spring clips. The edges of the base are slightly raised up as you can see, and the corners of the cylindrical finned section notched out. The processor makes direct contact with the central core (which is good), and the surrounding plate is only used to keep the heatsink in position.

Because the unit we tested was a prototype there were a few cosmetic differences you will see in this review. The fan impeller had been cut down from a larger size and so the edges of the blades were still a little fuzzy. This didn't impact the sound signature of the fan by any significant degree as the blade tips were cleaned up prior to testing. The base of the heatsink was held in place with an extra set of machine screws, but it is unlikely that this will be the case with the final commercial version. And lastly, there was some vibration issues due to the modified fan impeller which I expect would not be carried over to consumer versions using standard fan assemblies which are balanced.