Pin fin heatsinks have become rarer as the predominantly Taiwanese led heatsink industry advances its wares with inexpensive stacked arrays of copper and aluminum cooling fins. However, leading the charge against the trend is the Alpha Novatech PAL-8150 heatsink with it hundreds of cold-forged hexagonal aluminum pins. Alpha Novatech are a Japanese thermal solutions manufacturer, and coincidentally its heatsinks are in the majority of our servers owing to the reliability factor.

The dense forrest of black anodized aluminum cooling pins and swanky copper-embedded base are what makes the Alpha PAL-8150 a pretty attractive heatsink from the get-go. The model FrostyTech will be testing comes with an 80x80x25mm Delta AFB0812SH fan, so it is technically the PAL8150-M81 version. Similar units ship without fan, or with a lower profile 80mm square x 15mm thick fan.

A thin aluminum fan shroud wraps around the top of the Alpha PAL-8150 and extends down 25mm to direct airflow up to the fan through the base of the pin-fins. Alpha pin-fin heatsinks are generally designed to work best with fans which are mounted upside down, so that warm air is exhausted outwards from the top.

Alpha PAL-8150 Heatsink

HEATSINK SPECSHEET Manufacturer: Alpha Novatech Model No.: PAL-8150 M81 Materials: Microforged T6-6063 aluminum and copper 1100 base insert. Fan Mfg: Delta Electronics AFB0812SH Fan Spec: 4000RPM, 12V, 0.51A Fan Dim: 25x80x80mm Heatsink & Fan Dim: 104x81x80mm Weight: 715 grams Includes: printed instructions, mounting hardware, hefty K8 retention plate, thermal grease Compatible with Sockets: 754/939/940 Est. Pricing: $40USD ($44CDN)

The Alpha PAL-8150 heatsink is built to cool recent single and dual core AMD Athlon64/FX/X2 & AMD Opteron processors, and so it's compatible with all socket 939/940/754 CPUs. It should be noted given the imminent arrival of AMD's Socket AM2 Athlon64 CPU (a.k.a. Socket M2), that this heatsink won't be compatible with the four screw hole arrangement that socket is expected to introduce (see here and here). To apply the strong clamping forces on the integrated heatspreader that the AMD K8 processor specs require, the Alpha PAL-8150 heatsink uses a pair of machined 6-32 threaded stainless steel spring tensioned screws (with some rather massive springs).

The mounting screws are set at either end of the PAL-8150 K8 heatsink, and mesh up with either the motherboard PCB metal backing plate, or a rather hefty 3mm thick stainless steel plate Alpha include in the package. The documentation recommends replacing cheap plastic motherboard backing plates with this all metal unit. The backing plate is covered with 3M Scotch 467MP Hi Performance Adhesive, so once installed it will stay put while the motherboard is reinstalled into the computer case.

The hexagonal-shaped aluminum pin fins are arranged in a staggered orientation, and forged at the same moment as the aluminum base so it's a one piece affair. Set into the 9mm thick aluminum base is a 62x88mm plate of C1100 copper. The copper insert is about 3.5mm thick and makes direct contact with the CPU integrated heatspreader. Because copper is more thermally conductive than aluminum, it disperses the heat from the 38x38mm Athlon64 core out towards the edges of the heatsink more efficiently than if the base were solid aluminum.

This technique can make a heatsink perform better, but we'll have to wait until the thermal test results a little later to say definitively...