Thermal Paste Buying Guide: Which Paste, How Much and When to Replace It (2026)

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Between your processor and its cooler sits a layer that costs next to nothing and can still be worth a few degrees: thermal paste. According to ARCTIC, the surfaces of a processor and a cooler base are covered in microscopic unevenness. Without paste, that space stays filled with air, and air is a poor conductor of heat. The paste fills those gaps. This guide shows which paste fits your use case, how much you need, how to apply it and when it's time to replace it.

Transparency: We have not tested these pastes ourselves. All details come from ARCTIC, Noctua, Thermal Grizzly and the verified Amazon.de product pages (as of October 2026). We deliberately don't list prices because they change constantly.

When do you actually need new paste?

New cooler or new CPU: Many coolers include paste or come with it pre-applied. Check before you buy. More in the CPU cooler buying guide.
Cooler removed: Noctua recommends cleaning the CPU and cooler base every time you remove the cooler and applying fresh paste. Thermal Grizzly also says to use fresh paste when remounting.
Temperatures are rising: If your PC runs noticeably hotter than it used to under the same load and room temperature, old paste can be one cause.
Laptop, graphics card, console: Repasting is possible but more involved. Check your device's warranty terms first.

The key criteria

1. W/mK ratings: why they say little

Many pastes advertise a thermal conductivity in W/mK. The big manufacturers in this guide deliberately no longer do. Noctua doesn't publish figures because test methods aren't comparable and some vendors claim unrealistic numbers. Thermal Grizzly has not published blanket W/(m·K) figures since late 2020 because temperature, mounting pressure and contact surfaces affect the result. ARCTIC only lists a pointer to its FAQ instead of a number in the spec sheet. For you, that means: compare pastes using independent reviews, not the biggest number on the box.

2. Electrically conductive or not

All five pastes in this guide are not electrically conductive according to their makers. If some ends up in the wrong place, it won't cause a short. Liquid metal is different: Noctua points out that liquid metal conducts electricity and that even slightly too much of it in a laptop can cause a short circuit. A normal gaming PC doesn't need liquid metal.

3. Consistency and application

Pastes differ a lot in how thick they are, and that determines how you apply them:

Paste	Viscosity per manufacturer	How to apply it
ARCTIC MX-4	31,600 poise	spatula included, ARCTIC shows the method in a video
ARCTIC MX-7	35,000–38,000 poise	cross pattern, don't spread
ARCTIC MX-6	45,000 poise	not with a spatula, cooler pressure spreads it
Noctua NT-H2	not specified	doesn't need spreading, per Noctua
Thermal Grizzly Kryonaut	130–170 Pa·s	spread thin with the spatula

According to ARCTIC, thick pastes like MX-6 and MX-7 spread themselves under the cooler's mounting pressure. For Kryonaut, Thermal Grizzly recommends the opposite: spread it slowly with even pressure into a thin layer, without quick wiping motions.

4. Longevity and pump-out

Paste can lose effectiveness over time. Thermal Grizzly explains the so-called pump-out: constant temperature changes slowly push the paste out of the gap between chip and cooler. According to Noctua, laptops are particularly affected because the cooler sits directly on the chip and both expand differently. ARCTIC describes MX-7 as having no pump-out effect, and recommends MX-6 for chips without a heatspreader too, such as those on graphics cards and consoles.

Manufacturer figures for how long paste lasts on the CPU:

Noctua NT-H2: up to 5 years, often much longer
ARCTIC MX-4: at least 8 years, per the Amazon listing
Thermal Grizzly Kryonaut: no fixed interval, replace it when temperatures clearly rise

5. Pack size

One tube usually covers several applications. Noctua says 3.5 g of NT-H2 is enough for about 3 to 20 applications depending on CPU size: around 3 for very large Threadripper CPUs and, per the Amazon listing, around 15 for AM5 or LGA 1700. If you only mount a cooler once, a small tube is plenty.

6. Counterfeits

Popular pastes get copied. ARCTIC offers an Authenticity Check, and Thermal Grizzly includes a verification card with some packs. Ideally, buy offers sold by the manufacturer or fulfilled by Amazon.

How to apply it in five steps

Remove old paste: According to Noctua, a dry, lint-free tissue is enough. For a more thorough clean, use a tissue with a mild washing-up liquid solution; isopropyl alcohol works too but isn't necessary. Thermal Grizzly recommends a dry tissue first, then isopropyl alcohol or a cleaner.
Let it dry: Keep cleaner out of the socket and away from contacts.
Apply the paste: as the manufacturer says, i.e. a cross (MX-7), dots without spreading (NT-H2) or spread thin (Kryonaut).
Seat the cooler straight and tighten it evenly. Thermal Grizzly names even mounting pressure as the first thing to check if temperatures are too high.
Check temperatures: under load and at a known room temperature so you can compare later.

How much?

On laptops without a heatspreader, the paste sits directly on the small chip. Noctua recommends a drop of about 1–2 mm. For desktop CPUs, the surface should be covered thinly and completely. Thermal Grizzly says slightly too much paste won't make temperatures worse because the excess is squeezed out of the gap.

AMD AM5: The heatspreader of AM5 CPUs has cut-outs on the sides. According to Noctua, excess paste tends to collect there and is hard to remove. That's what the AM5 Edition of NT-H2 with its guard is for.

Five pastes on Amazon.de

Example model

All-rounder with cleaning wipes: ARCTIC MX-7 (4 g, incl. 6 MX Cleaner)

ARCTIC's newest paste is thick and applied in a cross pattern. The cooler spreads it during mounting. ARCTIC cites high long-term stability with no drying out and no pump-out. The set includes 6 MX Cleaner wipes to remove old paste. According to ARCTIC it suits CPUs, GPUs, laptops and console processors. Sold and shipped by ARCTIC GmbH, in stock (checked October 2026).

Amount: 4 g + 6 cleaning wipes
Viscosity: 35,000–38,000 poise
Operating temperature: −50 to 250 °C
Electrically conductive: no

Right for you if you want to remove old paste and apply new paste with everything in one set.

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Example model

Proven classic: ARCTIC MX-4 (8 g, incl. spatula)

According to ARCTIC, the MX-4 formula has stayed the same for years; only the packaging has changed. The paste is metal-free and not electrically conductive. A spatula is included. In the Amazon listing, ARCTIC states it lasts at least 8 years once applied. Seller at time of checking: ARCTIC GmbH, fulfilled by Amazon, in stock (checked November 2026).

Amount: 8 g + spatula
Viscosity: 31,600 poise
Operating temperature: −50 to 150 °C
Electrically conductive: no

Right for you if you want an affordable, proven paste for a CPU or GPU.

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Example model

Easy and long-lasting: Noctua NT-H2 (3.5 g)

The second generation of NT-H1. Noctua cites a new mix of metal oxide micro-particles for lower thermal resistance. The paste doesn't need to be spread before mounting the cooler. It comes with 3 cleaning wipes (NA-CW1) soaked in an isopropyl alcohol mixture. Noctua rates it for up to 5 years on the CPU and up to 2 years of use once opened. Seller: Noctua, fulfilled by Amazon, in stock (checked October 2026).

Amount: 3.5 g + 3 cleaning wipes
Enough for: approx. 3–20 applications
On the CPU: up to 5 years
Electrically conductive: no

Right for you if you want a paste that's easy to apply without spreading and easy to remove.

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Example model

For AMD AM5: Noctua NT-H2 AM5 Edition (3.5 g)

The same paste as NT-H2, but with the NA-TPG1 thermal paste guard. According to Noctua it stops excess paste from collecting in the side cut-outs of AM5 processors. The Amazon listing says one tube covers about 15 applications on AM5. Seller: Noctua, fulfilled by Amazon, in stock (checked October 2026).

Amount: 3.5 g + 3 cleaning wipes
Extra: NA-TPG1 guard for AM5
Enough for: approx. 15 applications on AM5
Electrically conductive: no

Right for you if you're installing a Ryzen 7000, 8000 or 9000 and want to keep the processor clean. Matching CPUs are in the CPU buying guide.

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Example model

For overclockers: Thermal Grizzly Kryonaut (1 g)

Thermal Grizzly developed Kryonaut for overclocking. According to the manufacturer it contains nano-aluminium and zinc oxide, isn't electrically conductive and doesn't cure. A spatula is included, and the paste is spread thin. Important: gaps over 0.2 mm (for example on VRAM or voltage regulators) need thermal pads, and for laptops Thermal Grizzly recommends its Duronaut pastes instead. Unopened, Kryonaut can be used for up to 10 years; opened, up to 5 years. Seller: procooling, fulfilled by Amazon, in stock (checked October 2026).

Amount: 1 g + spatula
Viscosity: 130–170 Pa·s
Working temperature: −250 to +350 °C
Electrically conductive: no

Right for you if you overclock your CPU and like spreading the paste evenly yourself.

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The pastes compared

Paste	Amount	Application	Extra
ARCTIC MX-7	4 g	cross pattern	6 cleaning wipes
ARCTIC MX-4	8 g	spatula included	metal-free
Noctua NT-H2	3.5 g	no spreading	3 cleaning wipes
Noctua NT-H2 AM5 Edition	3.5 g	no spreading	AM5 guard + 3 wipes
Thermal Grizzly Kryonaut	1 g	spread thin	spatula, for overclocking

Checklist before you buy

Does your new cooler already include paste?
Desktop CPU, graphics card, console or laptop? On laptops, watch out for pump-out.
AM5 CPU? Then the guard is worth it.
Do you have something to clean with: lint-free tissues, isopropyl alcohol or cleaning wipes?
Do you want to spread it yourself or let the cooler do the work?
Check seller and shipping to avoid counterfeits.

FAQ

How often should I replace thermal paste?

There's no fixed interval. Noctua rates NT-H2 for up to 5 years on the CPU and recommends checking temperatures occasionally after that. Thermal Grizzly advises replacing it when temperatures clearly rise or the cooler has been removed.

How much thermal paste do I need?

The contact surface should be covered thinly and completely. For laptop chips without a heatspreader, Noctua recommends a drop of about 1–2 mm. According to Thermal Grizzly, slightly too much isn't a problem because the excess gets squeezed out.

Can I reuse old paste?

No. Noctua and Thermal Grizzly recommend cleaning everything after removing the cooler and applying fresh paste.

What should I use to remove old thermal paste?

A dry, lint-free tissue; for a thorough clean, isopropyl alcohol, a mild washing-up liquid solution or dedicated cleaning wipes. Keep cleaner out of sockets and connectors.

Is an expensive paste much better?

Manufacturers like Noctua and Thermal Grizzly don't publish W/mK figures because they say little about real performance. How big the difference is for you depends on your CPU, cooler and mounting. Independent reviews are the best comparison.

Can I use regular thermal paste in a laptop?

Yes, NT-H2 for example, according to Noctua. However, paste in laptops can lose effectiveness over time due to pump-out. Liquid metal conducts electricity and is risky in a laptop.

Can thermal paste damage hardware?

The five pastes here are not electrically conductive according to their makers. Still, paste belongs only on the contact surface, not in the socket or on connector pins.

Sources

As of October 2026. Specs come from the manufacturers and the verified Amazon.de product pages (ASINs in the article body):

* Ad link: As an Amazon Associate I earn from qualifying purchases. Links go to Amazon.de – the price stays the same for you.