Thermalright XP-90 Heatsink Review

thermalright-xp-90

Introduction

In the arena of overclocking there seems to have been a trend over the past few years in the area of high end air coolers. The best of the best seemed to have several things in common, dense fin or pin arrays, and huge blocks of copper. One such trendsetter, Thermalright, has recently been turning heads with a new line of air coolers, the aluminum finned and heat pipe clad XP series. Today we are going to look at the AMD64 version of the XP-90 and see how it compares to a stock heatsink under overclocked and normal thermal loads.

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The heatsink comes packaged in a solid brown cardboard box, clad with Thermalright markings. Upon opening the box you can see that the packaging engineers knew what they were doing. The sink is suspended in cardboard, wrapped in plastic and it seems empty space was filled with foam.

After removing the heatsink package you can see that Thermalright incorporated every part into the package. Everything has its place. Maybe it’s just me, but I enjoy knowing that a company takes the extra steps to ensure that their product arrives to the customer in quality packaging. Thermal right also included a large list of accessories to make sure that you have everything you need for the installation.

Accessories included with the Heatsink include:

  • Mounting bracket
  • Screws
  • 92mm fan clips
  • 80mm fan clips
  • Rubber fan mounts
  • Large tube of thermal compound
  • Step by step mounting instructions
  • Even a Thermalright sticker

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What I was surprised to find however, after all of my boasts regarding Thermalright packing, was that some of the fins were bent on the side of the heatsink after removing it from the cardboard. Be careful, otherwise you will find yourself with a set of needle nose pliers, straitening fins for 10-20 minutes.

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Design
One thing you will notice the moment you unveil this heatsink its size. It is about 4 ½ inches long and 3 inches high. The design itself is comprised of an interlocking, dense array of aluminum fins. The fins extend down to the processor across roughly half its length.

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In addition to the fins there are four heat pipes. Heat pipes are closed metallic tubes that generally contain a phase change liquid in side. Heat is applied to one end of the pipe, which in turn changes the liquid to vapor where it moves to the other end of the pipe where heat can be removed. In this design the heat pipes are enclosed into a nickel plated copper base where heat from the processor will be applied and then whisked away and distributed to the top of the fin array.

Here a fan will remove the heat from the fins through forced convection. It seems the theory behind this design is to remove heat as quickly as possible (higher heat transfer rate – aluminum fins dissipate heat faster than copper using forced convection) as opposed to having a high heat capacity (large copper bases and fins – copper has a higher heat capacity and conduction rate than aluminum). This tends to explain such a drastic change from what many would consider a usual design from Thermalright.

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The heat pipes themselves are soldered to a flattened section of the fins of the heatsink. This provides drastic improvements in heat conduction from friction fitting or metal on metal contact. Heat pipes attached without solder would be similar to attaching a heatsink to a processor without thermal compound. Several things I noticed however was that the fins above the heatsink base have divets in three places (probably to increase air turbulence, increasing efficiency of forced convection) and that heat pipes in the base do not extend through the entire length.

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The base of the heatsink has been milled flat from a copper cast profile that has been nickel plated so that the aluminum fins can be soldered directly to it for better heat transfer. The base shows circular machining marks that you can feel when you run you’re your fingernail across it. Hand lapping the base could possibly improve this heatsinks performance.

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