Does Thermal Paste Expire?

Does thermal paste go bad?

Believe it or not, much like medicine and food, thermal paste also has a shelf life and can go bad. Generally manufacturers give their thermal paste a lifespan of 3 to 5 years. That’s if it sits under optimal conditions which may not be the case for you.

How to check if your thermal paste is expired

top down thermal paste

Has my thermal paste expired?

Well the dreaded answer is… it depends!

Different manufacturers use different compound mixtures and syringes. There are many brands including ARCTIC, Noctua, Thermal Grizzly, Arctic Silver, Coolaboratory, Cooler Master, and Corsair to name a few. So it’s hard to give a single answer.

If your thermal paste hasn’t been used since the last time you applied it to your CPU and was placed in a relatively normal temperature area with a tight seal then it should still be good.

Emphasis on should.

We recommend putting some on a metallic surface and spreading to check its consistency and smoothness.

If it has separated, comes out clumpy or watery, then throw it away and get yourself a new tube of thermal paste. You definitely don’t want this anywhere near your CPU and heat sink as a thermal paste’s consistency is crucial to regulating heat dissipation.

Worst case scenario you’re looking at very bad overheating that can possibly fry your CPU and motherboard.

How to properly store thermal paste

If you’ve got a relatively new tube of thermal paste and are worried about when it’s going to expire then you can prolong its life span by doing the following things:

  • Twist the cap back on to the thermal paste syringe tight enough. If this isn’t possible because of how the syringe is made then putting it in a Ziploc bag is the next best thing.
  • Don’t pull the plunger back. This the part you push with your thumb to get the thermal paste to come out. If you do then you will introduce air into the barrel and expose the remaining paste to oxidation.
  • Find an area with a normal room temperature. Nothing overly hot or cold and without being too humid. Avoid an attic or basement as these can get incredibly hot or cold depending on the season.
  • Cover the tube or place it in a box to avoid exposure to sunlight. A shelf drawer is likewise sufficient.

How often to replace thermal paste?

thermal paste left over

There are a couple scenarios when you should replace the thermal paste you have on your CPU and heat sink.

Every time you remove the heat sink off of your CPU you should replace the thermal paste. If you don’t do so then you will introduce air pockets when putting it back on because the way the paste was separated. This causes trouble when dissipating heat and can possibly damage your CPU.

So if, for example, you’re taking your heat sink off for a nice thorough cleaning of dust inside your PC then do yourself a favor. Wipe both the CPU and heat sink clean with isopropyl alcohol using a cotton swab or pad. Reapply some thermal paste and you’re set.

Some people go a step further and recommend replacing the thermal paste on your CPU every two to three years regardless of whether you touch the heat sink. Most seem to agree that doing it every year is a bit excessive.

If you have a prebuilt PC then we and others recommend replacing the thermal paste that came with no matter how old the PC. This is one of the easiest and cheapest ways to get some more performance out of your PC. Typically PC manufacturers cut corners to maximize profit through some mean. Be it through a cheaper case, lower quality thermal paste, or something else.

Does it make a difference?

A number of people have tested their CPU temps with old paste and newly applied paste.

What’s the result? Polarizing.

For some it’s lackluster while others see big improvements in temperature reduction.

This big disparity in results may be due to poor quality paste aging badly and as result showing a much greater improvement when replaced.

If you’re a tech and gaming enthusiast and like having your computer run like a finely tuned car that squeezes every performance advantage it can then more power to you. Your thermal paste would likely sit unused otherwise so it’s good to get the most out what you own.

Is too much thermal paste bad?

Yes, in fact poorly applied and excessive thermal paste has become a meme. The purpose of thermal paste to help with the conductivity of the CPU and heatsink. There is a point however where thermal paste will become an insulator if you put too much.

If you’re a novice you might think you’re doing more good by applying more paste, but this just isn’t the case. Too much will affect temperature regulation and in some cases overheat the CPU and actually do damage.

What happens if you don't use thermal paste?

Again conductivity will suffer and as a result so will the ability of CPU to displace heat. The CPU will operate at temperatures higher than necessary. If you’re stressing your CPU or overclocking this will lead to throttling or possible damage.

Given the low cost of a syringe there is no scenario in which not applying it makes sense.

I need new thermal paste

If it turns out that your thermal paste has indeed expired then get yourself a new one. Even the most expensive ones are reasonable when you factor the results in the reduction of CPU temp you might get! 

Through our years of experiencing with working and building our own PC builds we had the opportunity to test different pastes. The one we continuously come back to and recommend is the ARCTIC MX-4.

Thermal Conductivity8.5 W/mK
Viscosity870 Poise
Density2.5 g/cm³
Volume Resistivity3.8 x 10¹³ Ω-cm
Lifespan8 years
Dan Alder
Dan Alder
Dan's logged far too many hours in CS 1.6 and reminisces about LAN parties back in the good ol' days. He's also an engineer that's interested in anything to do with tech.
Dan Alder
Dan Alder
Dan's logged far too many hours in CS 1.6 and reminisces about LAN parties back in the good ol' days. He's also an engineer that's interested in anything to do with tech.

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