Comprehensive Guide On CPU Thermal Paste

Comprehensive Guide On CPU Thermal Paste


Martha Davis
August 15, 2021

Some minute components keep your performance-optimized PC running at the best state.

In most cases, you do not understand their importance until they stop working. CPU thermal paste is one of those products in the world of PC assembly.

It does not matter how much you have spent on the CPU; if you do not accompany it with the suitable CPU thermal paste, everything could be in vain. So, what exactly is CPU thermal paste?

How important is it when building a PC with stable performance? Most importantly, how do you manage the CPU thermal paste on your new or existing PC?

Here is a comprehensive guide on CPU thermal paste, where we have answered all these questions and beyond. Regardless of your experience with PC assembly and CPUs, you can use this guide to know what you should do about CPU thermal pastes.

What Is a Thermal Paste?

A thermal paste is a chemical compound with thermally conductive capabilities. It means the compound can conduct heat energy across the surface.

The compound should also be electrically insulating so that it does not allow current to pass through. A thermal paste is known by many names, such as thermal grease, Thermal Interface Material, CPU grease compound, thermal gel, heat sink paste, and thermal compound.

Although used across many semiconductor devices, thermal pastes are most commonly found with CPUs and GPUs. As you know, a CPU generates a considerable amount of heat when it is working.

A thermal paste makes sure that this heat is correctly passed onto the heat sink, which may further be connected to an air-cooler or water-cooling block.

Therefore, an effective thermal paste makes sure that the heat created from the CPU is disposed of properly. If this does not happen, you may face performance issues or hardware faults.

It should be noted that a CPU thermal paste does strengthen the connection between the CPU surface and the heat sink. However, sometimes, a thermal adhesive is added to the mixture to achieve this benefit.

On most days, thermal paste has the function of heat dissipation only.

As you can guess, you can find different types of thermal paste compounds in the market. You have to make the right choice based on the CPU/GPU use and the performance requirements. We will discuss these points in detail later.

How Is Thermal Paste Made?

How Is Thermal Paste Made?

We already mentioned that different types of CPU thermal pastes exist in the market. Therefore, the exact formula for the thermal paste compound may vary from case to case. However, some elements are common to all types.

Most manufacturers use a polymerizable liquid matrix and thermally conductive filler to make a CPU thermal paste. However, depending on the requirements, makers may choose one of the many matrix materials.

For example, you may find silicone grease, acrylates, and urethanes used as the liquid matrix. On the contrary, components such as aluminum oxide, zinc oxide, aluminum nitride, and boron nitride are used as the filler.

In the past years, demand for effective CPU thermal pastes has increased dramatically. So, many people may use liquid metal as the best ingredient for high-efficiency CPU heat sink compounds.

However, there have been a few concerns regarding the installation and maintenance of these metal-based CPU pastes. You will have to consider these points before you pick a side between standard and metal-based pastes.

You can find a lot of DIY articles on creating homemade alternatives for CPU thermal pastes.

While they may work, we do not recommend the DIY method due to safety concerns. Trust us; you do not want to take risks after spending almost a thousand dollars on a CPU and a heat sink.

How Does It Work?

CPU thermal pastes work in a more straightforward way than you think.

Of course, they manage to dissipate the heat produced from the CPU thanks to the thermally conductive and electrically insulative capacity. So, while the paste enables a constant heat transfer from the CPU, you do not have to worry about electric current passing through.

The materials commonly used to make a CPU thermal paste have these two primary qualities.

As we said in the introduction, CPU thermal pastes use a polymerizable liquid matrix. The molecules in these materials are arranged so close that not even the tiniest bit of air would not get in-between.

So, when you put one of these heat-sink compounds between the heat-sink and the CPU, it will eliminate all air gaps in the area. Nor can you find additional spaces in the particular region. So, it translates to the fact that heat can quickly move between the CPU and the heat-sink.

So, the next time the CPU generates heat, the heat gets transferred to the heat sink.

Depending on the CPU cooling system, fans or water blocks will push this heat out. In liquid cooling, the heat from the CPU is moved through cables until it reaches radiator fans. In air cooling, the air pushed out from the heat sink is further carried using the other fans inside the PC.

In either case, a CPU thermal paste works as a catalyst that makes heat dissipation effortless than ever before.

The amount of heat a CPU thermal paste can transfer depends on several factors, primarily the build quality. It is why you have to choose the best CPU paste according to your performance needs.

For instance, if you run the CPU at overclocked speeds, you cannot predict the amount of heat generated as a part of the process. In these cases, you need the best-in-class CPU heat-sink compound to ensure that your CPU stays safe and stable.

Why Is It Important to Use Thermal Paste?

portant to Use Thermal Paste?

Here are some of the compelling reasons to use a thermal paste with your CPU/GPU.

First and foremost, thermal pastes are necessary to keep your CPU in a healthy condition. As we said above, any CPU would generate a lot of heat when working. If this heat is left nearby the CPU, it will lead to colossal damage to the hardware.

In short, you can expect the CPU to stop working in a few months or so. To prevent the trapped heat from ruining your processor and other PC components, you should use a thermal paste.

A thermal paste ensures a smooth transfer of heat energy from the CPU to the heat sink. Given that you have set up an effective cooling system on top of the heat sink, you would not have to worry about the extra heat.

Even if we keep aside the problem of long-term damage, you cannot run a PC without proper thermal paste. You may be able to boot the system without any problem, but that is it. The CPU will heat up when you launch programs or processes, sending the internal temperature too high.

As a result, you can see BSOD, random PC shutdowns, screen stuttering, etc. Long story, it is almost impossible to start using a PC if it does not have an effective CPU thermal paste. In the same way, your GPU may also require thermal paste, but it is often pre-applied by the manufacturer.

By the way, the lack of thermal paste can lead to power throttling on some devices. Throttling is the process where the computer is slowed down to reduce the internal temperature. So, if there is no thermal paste, it will result in thermal throttling.

Finally, it is a wrong decision not to apply CPU thermal paste. As you can guess, a thermal cost does not cost a lot. The price is negligible when you have spent hundreds of dollars on a CPU.

And it does not make sense to let a super-expensive CPU go faulty because you could not apply a thermal paste. So, the least you can do is get one of the most affordable CPU thermal pastes in the market.

How Often Do You Need to Apply It?

How Often Do You Need to Apply It?

As you may know, CPU thermal pastes do not last a lifetime. The exact life of the paste would depend on its components. Therefore, you can find thermal pastes from manufacturers who claim either a few years or few months of life.

If you get one of the CPU thermal compounds with a short life, you will have to apply it multiple times a year. On the other hand, you would not have to worry about the frequent application if you can spend a little more and get a long-lasting variant.

Here is the thing, though. Since each PC is different, you cannot expect a thermal paste to last for the same time on all devices.

Instead, you have to consider factors such as the CPU type, its performance, and whether you are overclocking it. For instance, let us say that you bought a thermal paste that claims to last a year.

However, you have been using your PC at full speed with the CPU at overclocked frequencies. In that case, the thermal paste would be exhausted within a shorter period.

After all, you use a thermal paste to streamline the heat dissipation. So, if your PC generates more heat, it means the thermal paste would churn out quickly. If you ask for our advice, you should not wait until the exact expiry date of the thermal grease.

It is better to remove the old thermal paste and apply a new coat than risk the chance of running your PC without a coat of CPU thermal paste. You can confidently ignore the extra spending given the long-term health of your PC.

How to Remove Old Thermal Paste?

Removing old thermal paste from the CPU and the heatsink is easier said than done.

We should iterate that both the CPU and heat-sink are sensitive PC components. You do not want to rush and cause problems with either of these things, especially the CPU. We recommend following the steps given below as religiously as you can.

  1. First, you have to unmount the cooling system and keep the fan/water block aside.
  2. Now, you can remove the heat sink from the top. Make sure that you do not apply too much force.
  3. You should have a few drops of alcohol or a dedicated thermal surface purifier.
  4. Apply any of these materials on the existing thermal paste and wait for a few seconds as it spreads.
  5. At this point, shift to a microfiber cloth and remove the remaining parts of the CPU thermal paste.

You should ensure that you do not scratch the CPU surface.

If you cannot remove all the remaining chunks of the thermal paste, you can use a flat-shaped alternative to remove them. You may have to apply multiple coats of alcohol and microfiber wipes to keep things in check.

How to Add Thermal Paste?

Now that you have removed the old thermal paste from the CPU, we will add a new coat. Here are the simple steps to help you out.

Before we begin: a CPU thermal paste package would contain the paste and the applicator. You have to use the provided applicator for the best results.

  1. You can load the thermal paste compound in the provided applicator.
  2. Push the applicator to leave a small drop of the compound on the CPU surface
  3. Now, you have to place the heat sink on top of the CPU surface.
  4. Make sure that you apply equal pressure on four sides of the heat sink
  5. It will apply the thermal paste evenly on the CPU surface, thereby providing the best performance.
  6. Now, you can correctly screw in the heat sink, followed by the air/liquid cooling system.

Note: While using a small-sized droplet is the recommended method, some manufacturers may suggest a unique approach.

For instance, you can create a line of the thermal paste compound using the applicator. It might help you ensure an even spread of the thermal compound.


We believe we have answered all your questions regarding CPU thermal pastes.

As you have seen, they are nothing to be afraid of. As long as you choose one of the best thermal pastes and follow the steps precisely, you will have nothing to worry about.


Martha Davis

Martha Davis is a computer hardware specialist who works extensively in designing and manufacturing hardware devices, researching advanced computer technology. She built as a platform to share her insight on computers and PC assembly with the web. Currently, she is carrying out her research on Robotics and Computer Vision and working privately to deliver services. Martha makes sure that readers of master the basics of setting up computer components like motherboard, CPUs, and GPUs through the informative articles that she writes.