How To Apply Thermal Paste To Your Processor(CPU)



Category: CPU / APU, How To, PC & Hardware Guides

how to apply thermal paste

You may have probably heard about thermal paste, especially if you're in the world of PC building. Knowing how to apply thermal paste is a skill you must have to protect your CPU from heat. Nonetheless, we're here to guide you if this is your first attempt at applying thermal paste.

Thermal paste is the material that stands between your CPU cooling and your rig going up in smoke. Chances are you may have read about the horror stories associated with the wrong paste application. In addition, you may have come across different application methods, leaving you somewhat confused.

This guide will look at the step-by-step thermal paste application process, why each step is important and rookie mistakes to avoid when dealing with thermal paste. In addition, you will learn how to apply the correct amount to prevent guesswork.


What Is Thermal Paste?

Thermal paste is also known as CPU paste, thermal grease, thermal gel, thermal interface material(TIM) and heat paste. It is a thermally conductive compound applied above your CPU's IHS(integrated heat spreader).

The major role of this heat paste is to cool your CPU and keep it happy. This is done by improving contact between the heat source(processor) and the heat sink(cooler).

So, why not just attach the cooler to the CPU?

The CPU and the cooler are two flat surfaces. This means that directly placing them in contact would result in air gaps between the two surfaces, thanks to the microscopic imperfections on the cooler base and IHS surface. For this reason, thermal paste is applied to fill the gaps, forming a better physical connection.

In turn, there's greater, efficient heat dissipation, allowing your CPU to remain cool at all times.

Thermal paste is not to be confused with a thermal adhesive. The latter is used to bond the heat sink to an integrated circuit, while the former is a heat conductor and has no adhesive properties.

Key Terms You Need To Know

  1. CPU(Central Processing Unit) - Your PC's informational center. It executes operational instructions and sends instructions to other parts of the PC. Think of the CPU as the brain of your computer.

  2. IHS(Integrated Heat Sender) - This is the metallic lid of a CPU. It's also the part where you apply the thermal paste. The IHS helps distribute heat from the CPU(by acting as a heat sink) to the CPU cooler. In addition, it protects the processor's inner parts.

  3. CPU cooler - This is the part that helps your CPU to run at optimal temperatures. The cooler uses air or liquid to help dissipate heat from the processor.

  4. Base-plate - This is the metal base on the air cooler that attaches to the IHS of the CPU. The metallic design is specific to help heat transfer through convection. The heat reaches the fans in gas form to enable further redistribution.

  5. Water block - This part connects to the IHS when using an All-in-One liquid cooler. The liquid transfers heat from the IHS to a radiator through the heat transfer liquid.

Why Should You Apply Thermal Paste Correctly?

There are different ways to kill a rat or, in this case, apply thermal paste. However, your main concern should be applying the right amount rather than the method. This is because applying less thermal paste could significantly reduce the performance of your CPU.

Conversely, applying too much thermal paste could result in overheating and damage to your PC. For this reason, you need to ensure that you apply the correct amount for peak efficiency.

Another factor to consider when applying thermal paste is the type of processor in your rig, specifically the generation. This is because each CPU is different. For example, some CPUs have one die(chip), while others have multiple dies(chiplets). Additionally, this can be seen in the case of AMD Ryzen and Intel processors.

Ideally, since each processor is built differently, you want to ensure that you spread the thermal paste evenly across the IHS. In turn, this will guarantee great results while ensuring you don't apply too much thermal paste.

How To Apply Thermal Paste

how to apply thermal paste

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How Do You Prepare For Thermal Paste Application?

  1. Check if your processor has pre-applied thermal paste

    Some CPU coolers have a pre-applied thermal paste, making installation relatively easier, especially for newbies.

    If you're not sure if this is the case with your CPU cooler, check the bottom of the water block or base plate of your cooler(where it attaches to the CPU). If you see a silver paste, you don't need to reapply the thermal paste.

  2. Get the right thermal paste

    With more thermal pastes being produced every day, choosing the right one may be daunting. As such, it's recommended to go with the more expensive one since it has better performance. However, this is not always true. Fortunately, thermal pastes are not expensive, so spending a few extra bucks will not break the bank.

    Another tip is to go for a thermal paste tube resembling a medical string. This design ensures you don't apply too much thermal paste since you have to press to apply.

  3. Ensure the CPU and cooler surfaces are clean

    It's important to ensure that the CPU and cooler surfaces are clean before applying thermal paste. Start by using a microfiber cloth and isopropyl alcohol to remove old thermal paste residue from the CPU. You can also use cotton swabs or a paper towel in place of the microfiber cloth.

    You won't need to clean if you're building a new rig since these arts are new and squeaky clean. Also, check that the cooler doesn't have thermal paste residue when replacing the old thermal paste.

Thermal Paste Application - Step by Step

i). Install the Chip

Applying thermal paste is ideally the last step in your CPU cooler installation process. Therefore, ensure that the chip is installed on the motherboard and secured before applying the thermal compound.

In addition, if you apply paste to enhance thermal conductivity to the heat sink only to realize you forgot the backplate, you'll have to wipe down the paste and start a new application.

Follow up with the instructions manual to ensure you've completed all the steps up to attaching the cooler. Also, have any tools you need on standby.

ii). Apply the Thermal Paste

Now that the chip is tightly secured, it's time to attach the heat sink or water block. If there's a pre-applied silver paste on your CPU, there's no need to reapply thermal paste. If so, skip this step.

You'll need to apply thermal paste to a CPU IHS before placing the heat sink. As we had mentioned, there are many ways to go about the application process, from using a drop or a cross. Nonetheless, ensure that you factor in the size of the CPU chip the quality of paste you're using.

Also, ensure full coverage and that the paste has evenly spread on the surface. You can use the following ways to apply thermal paste:

a). Dot/ Pea Method

This is hands down the most popular and easiest method of applying thermal paste. It involves squeezing a thermal compound the size of a pea or grain of rice from the syringe and onto the center of your CPU'S IHS. Next, you'll need to lower the heat sink using a firm and even force.

Don't panic if you get some paste on the motherboard. Chances are, it is electrically non-conductive. However, ensure to confirm this first.

When using the pea or dot method, a general rule of thumb is to apply paste the size of the capacitors around the CPU. This ensures minimal spillage and reduces the chances of applying too much paste.

When placing the CPU cooler, ensure it's parallel to the IHS surface. Tighten the screws diagonally to ensure the thermal compound spreads out evenly.

b). Cross Method

The cross method involves drawing a straight line from one corner to the opposite. You'll then repeat this process on the ether end, so you have two lines intersecting in the middle. In addition, keep the lines inside the borders of the CPU rather than drawing them to the edges.

The next step is to lower the heat sink while ensuring an equal force distribution. You can use the process mentioned above.

c). Line Method

This method is relatively straightforward. Apply the paste in a line at the center of the CPU, then place the cooler on top. You want to avoid manually spreading out the paste. Instead of leaving that to the cooler pressure as you secure it in place.

You can also make a +(plus) pattern by adding a straight line at the center or placing two drops on either side of the line.

d). Spread Method

The spread method ensures the paste is spread all over the IHS rather than relying on the cooler pressure. Apart from the syringe, you'll need a spatula to use this method. Fortunately, many thermal pastes come with a spatula in the package anyway.

Apply a pea-sized dot on the IHS and use the plastic spatula to spread it around. Be sure to avoid spilling the paste on the edges, as cleaning can be daunting. Next, add the cooler, then tighten the screws to ensure even further spread.

iii). Install the CPU Cooler

Apply light pressure from the top when placing your cooler's water block or base plate to the IHS. Ideally, the force should be enough to prevent the cooler from sliding while evenly distributing the paste. However, ensure not to push hard as this could cause damage to the motherboard and CPU.

Another tip is to attach the cooler to the motherboard in a diagonal pattern as if drawing an "X." Place the screws but don't fully tighten them until all four have been attached. Next, ensure even pressure by turning each screw a few times before going to the next. Repeat until the cooler is securely attached.

iv). Counter-Check Your Work

This final step involves confirming if your installation was a success. Check that there's no spilled paste on the CPU edges or the motherboard. If so, it means you have applied excess paste and will need to clean it up. Use isopropyl alcohol to clean both your cooler and CPU, then apply a new thermal paste.

If the edges and motherboard look clean, check that the cooler doesn't move upon touching. If it's secure, congratulations, you have correctly applied thermal paste. Yaay!!

How Often Should You Replace Old Thermal Paste?

Generally, it would be best to replace thermal paste once every few years. However, should you happen to remove your cooler for any reason or if your CPU temperatures are climbing, then you should clean the old paste and reapply a new one.

What Should You Avoid During Thermal Paste Application?

  1. Applying the wrong amount - Applying the right amount of thermal paste helps ensure a more efficient transfer from the processor to the heatsink. On the other hand, an insufficient amount means covering a smaller surface area hence less efficiency.

    Conversely, applying a thick layer reduces efficacy since the metal surfaces are too far apart. In addition, too much paste increases the risk of spillage.

  2. Spreading thermal paste yourself - Tempting as it might be to spread out the paste, we advise leaving this task to the water block or base plate. This ensures the paste is spread evenly, thanks to the cooler pressure.

    Uneven paste distribution allows air bubbles to form, negatively affecting thermal conductivity and overall CPU temperature. In addition, this is counterintuitive since thermal paste fills air gaps to enhance conductivity.

  3. Reusing paste - Air bubbles can also form when you reuse paste. For this reason, in case a problem arises, prompting you to remove the cooler, we recommend that you clean off the paste then start a new application.

    You can only reuse paste when waiting for replacement thermal paste. However, keep in mind that this is a temporary solution and shouldn't be relied on for long-term CPU use.

Frequently Asked Questions


Although thermal paste is not often discussed compared to the monitor, processor and graphics card when building your own rig, it is an essential component to ensure the optimal performance of your gaming PC. Additionally, knowing how to apply thermal paste like a pro ensures a more efficient transfer.

You can use any of the methods listed in this article as they have proved efficient in conducting heat. However, if you're not too confident with applying the paste yourself, you can use thermal pads since they're easy and simple to install.

The methods mentioned above also come in handy when applying the thermal paste to your GPU. The reapplication period is also similar. However, it can be a challenging task depending on your GPU model.

Rather than treat it as an afterthought, we hope this guide shows you just how important thermal paste is when building a gaming PC.

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