A big thanks goes out to ThermalRight and Zalman for providing samples.

With Intel and overclockers pushing the Northwood core to speeds in excess of three gigahertz and beyond, cooling solutions have never been so prevalent. The Intel stock heatsink is a great performer in its own right, but better heatsinks are needed by overclockers to push the limits of their processors. Here we have three high end Pentium 4 coolers ranging Alpha using their traditional forged pin design, ThermalRight with an offshoot of the popular Athlon-based AX7, and Zalman with a revision to their paradigm bending flower design.

Alpha PAL8942T

Material: Copper/Aluminum Hybrid
Size: 78.5mmx90×42 (LxWxH)
Weight: 534g
Bundle: Heatsink, fan shroud, mounting hardware

Alpha has always been associated with high performance coolers. This heatsink is a hybrid, like many others on the market today. The common misconception used to rationalize these designs is aluminum dissipates heat more quickly while copper can absorb it more quickly. The real reason behind this design is to maximize the efficiency of the heatsink based on weight. Copper does have a higher conductivity than aluminum by volume, but aluminum has a higher conductivity by mass. Using a hybrid of these metals gives the best trade off between conductivity and weight. The base is made from a solid piece of copper which has been machined to be quite smooth and flat, despite the presence of machining swirls. Using their forging technique the aluminum pins are, for all intents and purposes, a part of the copper base allowing for the best heat transfer possible. These hexagonal pins are anodized black, meaning that aluminum oxide has been “grown” on the surface of the aluminum creating a very hard coating. Anodizing does not hurt performance except when used on the mating surface with the processor because of its extremely porous and crystalline structure; that’s why it can accept dies readily. The Alpha comes with an aluminum shroud to direct air flow as well as raise the fan above the heatsink about five millimeters to reduce the dead-spot underneath the fan rotor. 

The worst aspect of the Alpha is the mounting system. Instead of using the standard retention mechanism, the heatsink must be installed via the four mounting holes around the socket, necessitating the removal of the retention mechanism and motherboard. Each of the four holes requires one standoff, two washers and one nut. Once they are installed, the heatsink needs to be screwed into the standoffs. To maintain even pressure on the processor, the screws have to be tightened little by little (in the same fashion as installing a tire) until the screws have bottomed out. The shroud simply drops onto the heatsink and the fan is screwed into the heatsink base. Alpha does not bundle a fan, thus allowing end users to customize the heatsink to their needs. Installation really is not a hassle if only done once, but is quite a pain of done many times. Often times the standoffs will release from the motherboard when removing the heatsink causing me to go on an hour hunt for tiny, clear washers; for a semipermanant solution, a drop of superglue would do the trick.