How Often Should You Replace Thermal Paste?

Thermal paste is an important part of any PC build because it protects the central processing unit from overheating, which can cause a variety of serious issues. However, you may not know everything you need to know about this material, including how often you need to replace it.

You should replace thermal paste every two to three years, whenever you remove the central processing unit, whenever you notice your paste is dry or flaky, or as soon as your central processing unit shows signs of overheating.

The rest of this article will answer all your questions about thermal paste, its longevity, how it works, and how to apply it. So, if you’re working on a PC build, or if you’re looking for ways to improve the build you already have, keep reading!

Thermal paste being applied to a CPU.

Indications that you should replace the thermal paste

Since several factors influence how long thermal paste lasts, it’s difficult to determine a specific time to replace the thermal paste.

However, a general rule is that once every few years should be sufficient. Three years is probably the average number of years to go before replacing the thermal paste, although it may depend on your computer’s wear and tear and how often you use it.

If you’re upgrading or replacing your central processing unit (CPU), you’ll need to replace the thermal paste too because you can’t reuse it.

Old thermal paste may be able to leave air bubbles that will reduce heat transfer efficiency.

Another indicator that it’s time to replace the thermal paste is if you notice that your old paste is dry and flaky.

If this is the case, the paste is no longer operating to the best of its ability, and your CPU is in danger of overheating.

If your CPU does seem to be heating up regularly, this is another sign that the thermal paste is no longer doing its job and needs replacement.

The following factors influence how long the thermal paste will last:

  • How high your CPU temperatures get and how frequently it’s at a high temperature.
  • The brand and type of your paste.
  • The airflow of your PC tower.

In general, once every three years should be often enough to replace the thermal paste.

How to apply thermal paste

Removal of old thermal paste from a CPU heatsink.

Before you begin applying your paste, clean your central processing unit. If you’re replacing old paste, you’ll need to remove it.

To do this, put some thermal paste remover on a microfiber cloth and rub the old thermal paste away.

Keep applying thermal paste remover to clean areas of the cloth and repeat the cleaning process until all the old thermal paste is completely gone.

Important: Never use a scraping device of any kind to remove old thermal paste. Thermal paste remover is awesome and will make short work of any old dry paste.

Then apply some surface purifier fluid to make sure that the surface is properly prepared.

Make sure the CPU dries completely before you begin the process of applying the new paste.

I like to take a clean microfiber cloth at the end to remove the last bit of surface purifier that may be left to ensure the surface is dry.

Make sure no particles of dust or other debris makes their way onto either surface, especially after you have applied thermal paste. You can even use a little compressed air to ensure the area is dust-free before applying the thermal paste.

This product is specifically made for this job and you won’t find a better type of solution to make cleaning up old thermal paste easier.

After the CPU is clean and dry, you’re ready to apply the new thermal paste. Here’s how: 

  1. Apply the thermal paste onto the center of the central processing unit’s lid. You don’t need a lot of paste: a pea-sized amount will suffice. This lid also called an integrated heat spreader, is the heat sink that distributes heat from the processor to the CPU cooler. If your paste came with an applicator, you could use this tool to spread the paste out evenly before clamping the heat sink down.
  2. Place the cooler onto the CPU. You should do this with enough force that the cooler doesn’t slide around but gently enough that you don’t cause any damage.
  3. Attach the cooler to the motherboard. Attach in a diagonal pattern.
  4. Check to make sure everything looks correct. There shouldn’t be any paste spilling out, and everything should look clean and secure.
Fresh thermal paste being applied to a clean CPU surface.

If you did apply too much paste and some is spilling out onto the motherboard, you’ll need to clean it off with thermal paster remover and start the process over again.

How does thermal paste work?

Thermal paste works by transferring heat away from the central processing unit of a computer and into the heat sink to prevent the CPU from overheating. The paste seals gaps in the hardware to increase heat transfer efficiency.

Thermal paste is also called thermal grease, CPU paste, thermal gel, thermal interface material, and heat paste.

This paste is applied between the processor and the heat sink to protect the CPU.

The heat sink and the CPU are close together, but the heat sink has grooves and gaps that allow air between the CPU and the heat sink, reducing heat transfer because air is a terrible thermal conductor.

Thermal paste fills these holes to create a tighter seal that allows for better heat transfer.

There are three types of thermal pastes:

  • Metal-based. Metal-based pastes contain metal particles, usually aluminum or silver. This type is the most effective for lowering temperatures. However, you have to be careful when handling this kind of paste, as a spill on the motherboard could lead to short-circuiting and damage. This is also the most expensive kind of thermal paste.
  • Ceramic-based. This kind of paste contains ceramic powder, usually made with aluminum oxide and zinc oxide. This kind of paste is inexpensive and won’t cause electrical damage in the event of a spill. They are less effective in heat transfer than metal-based pastes, though.
  • Carbon-based. This kind of paste contains carbon particles and other materials, such as graphene oxide. These pastes don’t conduct electricity, so just like ceramic-based pastes, they won’t cause electrical damage if you spill them. Carbon-based pastes perform only slightly worse than metal-based pastes in lowering temperatures.

A computer will start without thermal paste, so some mistakenly believe that it’s not an essential part of building a computer. However, without thermal paste, the CPU will most likely overheat, which can cause the following problems:

  • Blue screen errors.
  • Software crash.
  • Loss of data.
  • Destruction of internal components.
  • OS slows down.
  • Spontaneous reboots.
  • Regular crashing.
  • Computer freezes.
  • Loud computer fan sounds.
  • Pixelated lines on the screen.
  • Damage to the motherboard.

In serious cases, the computer may even catch fire! Therefore, it’s essential that you keep the CPU in your computer nice and cool, and thermal paste is a great way to do this.

Thermal pads vs. thermal paste

Thermal pad being placed on GPU inside a laptop with one already placed on the CPU.

An alternative to using thermal paste is using thermal pads instead.

Thermal pads are pieces that are thermally conductive material, usually silicon, that are positioned between the CPU and the heat sink to help conduct the heat.

The purpose of a thermal pad is the same as thermal paste.

Whichever you choose is a matter of your personal preference, as each method has advantages and disadvantages. The following table outlines these pros and cons:

Type of Cooling MethodProsCons
Thermal Paste
  • Spreads easily
  • Conforms to uneven surfaces
  • Fills large holes more evenly than pads
  • Better thermal conductivity when applied in a thin layer
  • Most pastes are less expensive than thermal pads
  • Messy application process
  • Dries out
  • Can’t be reused
Thermal Pads
  • Clean application
  • You can cut the pads to certain sizes to fit your specific setup
  • Can fill bigger holes
  • More expensive than paste
  • Thicker material means less effective thermal conductivity

However, this isn’t my preferred choice. In my personal opinion, thermal pads work well for heatsinks that contain a small gap away from the surface of the area that needs to be cooled.

The choice of paste or pads is truly up to you and your personal preference. As long as you have some sort of cooling mechanism, your CPU will thank you.

Alternatives to thermal paste

If you don’t have access to thermal paste for whatever reason, there are alternative solutions that you can make or use that will have a similar cooling effect for a temporary fix.

Please note: These are temporary fixes and that you should apply thermal paste as soon as you can! These solutions are not recommended.

  • Hazelnut spread, such as Nutella. Hazelnut spreads have a soft consistency similar to thermal paste, and they can work as cooling agents in a pinch.
  • Toothpaste and vaseline. Mixing some vaseline with some toothpaste will help it dry slower. This solution can last for 3-4 months.
  • Butter. The smooth consistency of butter, like hazelnut spread, can also help transfer heat. This solution won’t last very long, though.
  • Diaper rash cream. The zinc oxide in this cream works well for transferring heat, and this fix can last 5-6 months.
  • Moisturizing cream. Some moisturizing creams also have zinc oxide, but the smooth and slick cream will help transfer heat away from your CPU even if they don’t.
  • Beeswax. If you use beeswax, make sure that it is pure, 100% beeswax. This will only work for a few days before it becomes brittle and ineffective.
  • Sealing wax. You’ll need multiple layers of this for it to be effective, but non-pigmented sealing wax can work for a few days to keep your CPU cool.

These solutions will work for a while, but it’s best to get your hands on some thermal paste as soon as possible for the best results.

Other ways to keep your CPU cool

An aftermarket air CPU cooler.

If you use your PC a lot or frequently play games that cause your PC to work hard, you shouldn’t rely only on thermal paste to keep your CPU from overheating.

Thermal pastes can be extremely effective, but you should combine the paste with other ways to keep your computer cool for the best results and ensure your PC’s longevity. 

Here are some other ways to keep your computer cool:

  • Clean your computer’s case regularly. Any dust or debris that builds up in your computer’s case can block the airflow, which can cause the CPU to overheat more. To avoid this issue, you should clean your computer’s case before it becomes a problem.
  • Put your setup in a place where it can get good airflow. If you shove your PC setup in an enclosed space, such as against a wall where air cannot circulate as well, you’re not setting your PC up for success. Ensure that the vents are unblocked and remove any obstacles that restrict airflow. There should be 2-3 inches (5.08-7.62 centimeters) of open space on either side of your case, and the back should be completely open.
  • Don’t keep your set up near a window. If your setup is near a window exposed to sunlight, this can lead to overheating.
  • Upgrade to a high-quality CPU fan. Your CPU probably came with a fan preinstalled, but these fans are usually low-quality and don’t work very well. Consider an upgrade if you want to keep your CPU working to the best of its ability!
  • Add more fans. If your CPU is overheating regularly, you may need to add more fans to your setup to increase airflow. If you don’t already have case and memory cooling fans, it is a good idea to add these.
  • Use a water cooling kit. Water cooling kits use pumps for cycling cold water to the CPU and then out of the system. The coolant in the kit absorbs heat as it moves through the system and then uses fans to move the heat away from the CPU. An AIO is a great solution, it is easy to install and requires very little maintenance.
  • Stop overclocking. Overclocking is when you run your computer’s processor at a higher speed than the manufacturer intended, which is a major cause of overheating. If you’re not keeping the hardware that you’re overworking cool, your computer will overheat and experience technical difficulties.
  • Invest in a phase change unit. A phase change unit is like a refrigerator for your CPU. These units can be expensive, but they are extremely effective.

If you take these steps and use a high-quality thermal paste, your PC most likely won’t overheat as much, and you’ll have a healthier system overall.

Conclusion

Thermal paste is a great tool for helping your PC build stay functional and healthy for as long as possible.

As long as you replace it every three years, whenever you remove the CPU, whenever you notice a dry texture, or when your CPU begins to overheat, thermal paste can help you maintain an effective PC system.

You can also combine thermal paste with other cooling methods for the best results.