How to Install a CPU Cooler

You don't need an electrical engineering degree to properly install a cooler on your CPU. As is the case when installing many PC components, however, the procedure involves some subtleties that can have a measurable impact on the computer's performance.

Simply latching on a CPU cooler without doing additional prep work may result in a seemingly perfect, working system. However, if you take some extra time to thoroughly clean the CPU’s integrated heat spreader and heat sink, prime their surfaces, and properly install a high-quality thermal interface material, your CPU's temperatures will be lower--sometimes much lower. And lower CPU temperatures often result in a quieter system that’s also more stable and overclockable, if that’s your thing. A cooler chip is likely to hold up longer under sustained use, too.

With all of the potential benefits to a properly installed CPU cooler, we thought it would be a good idea to take you through the installation process, step by step, with both AMD- and Intel-based systems. Keep in mind that while we focus on desktop processors here, the steps outlined in this article generally apply to all types of processors, and to other chips that require heat sinks to aid in cooling.

Installing a Cooler on an AMD Processor

Although current AMD desktop processors make use of a few different socket types (AM2, AM3, AM3+ and FM1), the CPU-cooler installation process is similar for them all.

Ensure that your AMD processor is fully inserted into its socket.

Step 1: Ensure That the CPU Is Fully Inserted Into Its Socket

Unless something is obstructing the processor and preventing it from being perfectly seated in its socket, the chip should sit flat and level. To be certain it’s installed correctly, lift the socket retention lever and apply a bit of downward pressure on the CPU. Then, while applying the pressure, lower the lever to lock the CPU into place. Finally, perform a final visual inspection to confirm that the CPU is fully seated and flat against the socket.

Step 2: Clean the CPU and Heat-Sink Surfaces

For the base of the cooler’s heat sink to make optimal contact with the CPU’s integrated heat spreader, both surfaces must be clean and free from contaminants or particles. Use a lint-free cloth and a small amount of isopropyl alcohol (or an alcohol-based cleaner safe for use on electronics, which won’t leave behind any residue), to clean the base of the heat sink and the top of the CPU’s integrated heat spreader. It’s important to remove adhesive or any other potential contaminants that may prevent the surfaces from mating properly.

Carefully clean the CPU and prime it before installing the heat sink.

Step 3: Prime the CPU and Heat-Sink Surfaces With Thermal Paste

Some people argue that this step is unnecessary, but we’ve been doing it for years with great success. The reason for using a thermal interface material, or TIM, between the heat sink and CPU is to minimize or eliminate any potential air gaps. The TIM is a better conductor of heat than air is, and it acts as a medium to facilitate the migration of heat from the CPU to the heat sink. Priming the surfaces with a small amount of thermal paste (our TIM of choice) will fill in the microscopic imperfections in the metal that may not be filled by the final application of thermal interface material as the heat sink compresses it. Priming the surfaces also lubricates them somewhat, and helps to ensure that the final application of TIM spreads more easily and more evenly when compressed.

To prime the CPU’s integrated heat spreader and the heat sink’s base, apply a very small amount of thermal paste to each and rub it into their surfaces with a circular motion, as if you were waxing a car. The goal is to work the paste into the imperfections in the surface, until you’re left with what looks like a slight haze in the metal.

Use a very small amount of thermal paste on the CPU.

Step 4: Apply the Thermal Interface Material

With the CPU’s integrated heat spreader and the heat sink’s base clean and primed, it’s time to apply some thermal interface material, preferably a high-quality ceramic or silver-based thermal paste. On the center of the CPU’s integrated heat spreader, apply a small amount of thermal paste--just enough to cover the metal surface with a paper-thin layer of paste when spread out. A drop barely larger than a BB but smaller than a pea will do. You do not want gobs of extra paste to ooze from the sides when you mount the heat sink. The goal is to use the least amount of thermal paste possible to cover the surface of the integrated heat spreader, eliminate any air gaps, and allow maximum thermal transfer between the integrated heat spreader and the heat sink. Using too much thermal paste can hinder performance, so be judicious in its application.

Try to mount the cooler so that there are no air gaps between it and the CPU.

Step 5: Mount the CPU Cooler

Most air coolers for AMD processors use a simple clip/latching mechanism to secure the heat-sink assemblies to the socket. The installation process involves lowering the heat sink in place, latching two clips to the mounting bracket around the CPU socket, and firmly securing the heat sink with whatever locking mechanism is installed on the cooler, typically a lever with a cam or screws.

The cooler we used, a model from Thermaltake, had a simple lever with a cam. To install it, we lowered it into position, being careful to hold it level and parallel to the CPU’s surface to ensure that the thermal paste spread evenly in all directions. Then, we positioned the metal clips over the hooks on the mounting bracket, and while applying a bit of downward pressure on the heat sink, we moved the lever into the locked position. The cam on the lever engages with a metal place on the mounting bracket, and applies constant downward pressure on the heat sink so that it makes good contact with the CPU surface.

Finally, plug the cooling fan’s connector into the CPU fan header on the motherboard, and you’re done.

Next page: Installing a cooler on an Intel processor

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