Thermal Grease on CPU
Thermal Grease on CPU

Thermal grease, also known as thermal paste or thermal compound, is a substance placed between the CPU and the heat sink to improve heat conduction. Over time, this paste can degrade and may need to be replaced to maintain optimal cooling performance. When you try to remove it off an old CPU (or other device) you might notice it’s hard, dry, crusty and very difficult to remove.

Why Clean Thermal Grease Off An Old CPU?

Old thermal grease can become ineffective, causing the CPU to overheat and potentially damage the computer. Regular maintenance, including cleaning off and replacing the thermal grease, can significantly prolong your CPU’s life.

Gathering the Necessary Supplies

Before you begin, gather the necessary supplies: a soft cloth or lint-free wipes, isopropyl alcohol (99% preferred), a thermal compound, and a static-free workspace.

Safely Removing the CPU

The first step is to safely remove the CPU from your computer. Remember to ground yourself to avoid static damage and carefully unlock and lift the CPU from its socket.

Removing the Old Thermal Grease

With the CPU removed, apply a small amount of isopropyl alcohol to the cloth and gently rub the surface of the CPU to remove the old thermal grease. Be careful not to apply too much force to avoid damaging the CPU.

Applying the New Thermal Grease

After cleaning, let the CPU dry completely. Then, apply a small amount of new thermal grease on the CPU surface. Remember, less is more – you don’t want the paste overflowing when the CPU is reinstalled.

Reinstalling the CPU

Once the new thermal paste is applied, you can carefully reinstall the CPU. Ensure it fits properly in its socket, and then reattach the heat sink and fan.


Why do I need to clean off the old thermal grease?

Old thermal grease can lose its effectiveness over time, causing your CPU to overheat. Cleaning off the old paste and applying a new layer can help keep your CPU cool and prolong its life.

What supplies do I need to clean thermal grease off a CPU?

To clean thermal grease off a CPU, you’ll need a soft cloth or lint-free wipes, isopropyl alcohol, and a new thermal compound.

How often should I replace the thermal grease?

The frequency of replacing thermal grease depends on your CPU usage and temperatures. However, as a general rule of thumb, it’s a good idea to replace it every 2-3 years.

Can I use rubbing alcohol to clean thermal grease off a CPU?

Yes, you can use rubbing alcohol, but it’s preferable to use 99% isopropyl alcohol. It evaporates quickly, leaving no residue.


Cleaning thermal grease off an old CPU is an essential maintenance task that can help prolong your computer’s lifespan. By following the right steps and precautions, you can effectively clean and reapply thermal grease, ensuring your CPU stays cool and performs optimally.

Eric Chan

Hi! I’m Eric and I work on the knowledge base at  You can see some of my writings about technology, cellphone repair, and computer repair here.

When I’m not writing about tech I’m playing with my dog or hanging out with my girlfriend.

Shoot me a message at if you want to see a topic discussed or have a correction on something I’ve written.

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