How to apply thermal paste

Needing to know how to apply thermal paste may not be something you’ve had to deal with so far if you’ve freshly installed a CPU before, or if any coolers you’ve purchased have come with paste pre-applied. But it’s important to know what you’re doing before undertaking it by yourself, as doing it wrong could result in damage to your computer’s hardware. If you haven’t purchased a thermal paste yet, check out our best thermal paste for CPU and GPU in 2023 for our top picks. 

What thermal paste is and why you need it

If you’ve never made alterations to your PC’s hardware before, or aren’t familiar with CPU cooling, you may be wondering what thermal paste is, or why you need it. Put simply, CPUs (and GPUs) can overheat like any piece of hardware, they generate heat when in use, and if the heat has no means of efficient distribution, the CPU’s temperature will exceed its optimal operating temperature. This can negatively affect the running of your PC, as if the temperature reaches its maximum limit the CPU throttles, slowing down to reduce the heat being produced. This will become apparent by your PC being sluggish or unstable, shutting down randomly or becoming unresponsive at intervals. It could also result in the processor failing entirely, all the more reason to invest in one of the best CPU coolers. 

This will naturally be quite inconvenient when you’re mid-game, so the best way to avoid overheating is by installing a cooler. This can be an air cooler or a liquid cooler, there are pros and cons to both, and I would recommend checking out the best CPU cooler for gaming in 2023 to help pick the best one for you. 

Explained simply by Intel, the ‘lid’ of your CPU (IHS) may appear to have a smooth surface, but it actually has microscopic imperfections that hinder heat transfer. The metal base of your CPU cooler also has these imperfections, which means when placed on top of the IHS, there are air gaps. This is where the paste comes in, as it fills the gap between the two to ensure efficient heat transfer. 

Before you start

It’s important to check all instructions before you try and attach the cooler to your CPU to ensure no damage is done to the hardware. It’s also crucial to ensure that your CPU is clean, and doesn’t have any previous thermal paste on it. Reusing thermal paste can result in air bubbles that reduce the quality of the heat transfer and can lead to throttling. Likewise, check if your cooler has heat paste pre-applied, as then there may not be a need to add more, depending on the quality of the paste, in some cases you may be better off removing it and applying your own. I would also recommend you make sure your cooler is completely ready to be installed before you apply paste. 

Step by step

1. Apply thermal paste to the centre of the CPU’s ‘lid’ (IHS) – roughly a pea-size amount is recommended. Larger CPUs may need more paste to cover the surface, as pointed out by PC Gamer, and while there are various different patterns debated by enthusiasts, one dot in the middle will probably be good enough. Alternatively there’s the cross method where you draw an X and can provide full coverage as well, but we don’t recommend manually spreading it around. Install the CPU cooler as straight as possible, if you move it too much when it makes contact with the paste, you’ll probably have to start the process again. Lower the cooler with a light amount of pressure, aligned as near perfectly with the CPU as possible. 
2. Keep the cooler in place as you attach it to the mounting mechanism. Don’t push too hard.
3. Insert the necessary screws. Intel recommends you do not tighten the screws one by one, as this will create a pressure imbalance that may spread the paste around too much. Tighten each screw gradually to ensure even pressure, until they are all secure. 
4. Double check everything is attached correctly. There shouldn’t be any thermal paste seeping over the edges or onto the motherboard – if there is, clean it quickly and then begin again. If there is no thermal paste out of place and everything is attached correctly, you’re good to go!

How often you should change your thermal paste

The consensus on how frequently you should change your thermal paste does vary, but in general it is recommended by Intel that every few years is a good length of time to leave before thinking about replacing the paste. That being said, if you remove your CPU cooler for any reason, you should reapply the thermal paste and follow the above steps again. 

Thermal paste can last for quite a while, even up to a decade, though this can be affected by various factors. Kooling Monster points out that the regularity with which you change your thermal paste does depend on the quality of the thermal paste and the PC components. As well, if you are an avid gamer you will likely have a regular, demanding use of your PC, and this will affect how long your paste will last. Thermal paste decays and dries out over time, especially if it is a lower quality paste, and the more strain your CPU and its cooler are under, the shorter the ‘shelf life’ of the thermal paste will be. 

As the efficiency of your thermal paste’s heat transfer worsens, be it because of high demand on your CPU or just general decay over time, you’ll likely spot the symptoms. Your CPU will begin to throttle if it overheats, which can lead to an unstable and unresponsive PC. If you’ve noticed that the quality of your display is getting worse or the running of software is a struggle, it’s probably time to check your thermal paste and think about replacing it. 

What is the best way to apply thermal paste?

There are various different patterns debated by enthusiasts, but generally one pea-sized dot in the middle will be enough. For a bigger CPU you may need a larger amount. 

What do you spread thermal paste with?

Some suggest using something like a credit card to ensure the paste is spread evenly. But you should not spread it manually as this can lead to air bubbles and uneven distribution of the paste. Let the pressure of the cooler spread the paste as this ensures good distribution.

How often should thermal paste be changed?

Every few years depending on the way you use your PC and the quality of the thermal paste. If you start noticing performance issues when running your computer, it likely means the thermal paste has degraded and should be changed to prevent your CPU from overheating.

(Image Credit: NZXT)