Buying Guide

The Best Thermal Pastes for CPUs and GPUs

Seven thermal pastes compared on durability, conductivity, tube size and what comes in the box, for CPU installs and GPU repasting.

By The PC Journal editorial team

13 min read7 products evaluated

Among reputable thermal pastes, temperatures usually differ by only a few degrees. What separates them is how long they last on a hot CPU, whether they are safe if they spill and how easy they are to apply.

We compared seven pastes on the maker's durability claims, electrical safety, tube size and included tools. This is a research-based comparison built from maker specifications; we did not test these parts ourselves. Conductivity figures are the makers' own and are not measured on a common standard, so we do not rank on them.

Quick Picks

Our 7 recommendations at a glance. Tap a pick for the full verdict.

  1. Most Durable Pick

    ARCTIC MX-7 (4g)

    A formula built against pump-out and dry-out.

    Best for: Hot CPUs you do not want to repaste.

    Our take Check price for ARCTIC MX-7 (4g) (opens in a new tab)

  2. Best Value

    ARCTIC MX-6 (4g)

    4g of non-conductive paste suited to direct-die use.

    Best for: Regular builders and GPU repasting.

    Our take Check price for ARCTIC MX-6 (4g) (opens in a new tab)

  3. Solid Alternative

    Thermal Grizzly Duronaut (2g)

    Duronaut is Thermal Grizzly's long-life paste, built to minimise pump-out and sold with a spatula.

    Best for: Buyers who want electrically non-conductive, so spills are harmless.

    Our take Check price for Thermal Grizzly Duronaut (2g) (opens in a new tab)

  4. Easiest to Apply

    Noctua NT-H2 (3.5g)

    No spreading needed, with three wipes included.

    Best for: First-time builders.

    Our take Check price for Noctua NT-H2 (3.5g) (opens in a new tab)

  5. Best Small Tube

    Thermal Grizzly Kryonaut (1g)

    A 1g syringe with spatula.

    Best for: A single build or remount.

    Our take Check price for Thermal Grizzly Kryonaut (1g) (opens in a new tab)

  6. Worth Considering

    Thermalright TF7 (2g)

    TF7 offers 12.8 W/mK and a wide temperature range in a non-conductive formula.

    Best for: Buyers who want maker-rated 12.8 w/mk conductivity.

    Our take Check price for Thermalright TF7 (2g) (opens in a new tab)

  7. Well-Rounded Choice

    Corsair XTM70 (3g)

    XTM70 includes an applicator kit and three wipes, with a low viscosity that spreads easily.

    Best for: Buyers who want includes an applicator kit and three cleaning wipes.

    Our take Check price for Corsair XTM70 (3g) (opens in a new tab)

Our Picks

ARCTIC MX-7 (4g)

Most Durable Pick1 of 7

ARCTIC MX-7 (4g) on Amazon (opens in a new tab)

MX-7 is Arctic's dense, high-filler paste, built to resist pump-out and drying on hot CPUs.

Best for

Hot CPUs you do not want to repaste.

Skip if

Price-first buyers should look at the TF7, which cost less when we checked.

Why we like it

It cannot be spread by hand, so apply a dot and let the cooler's pressure do the work. It matches the MX-6 on tube size (4g). Clean off old paste with isopropyl alcohol first, then apply a pea-sized dot or a thin line on the heatspreader; on large Intel chips an X or a line covers the longer die better.

Do not pre-spread it; let the cooler's mounting pressure distribute it. It also brings 4g is enough for several applications. Worth noting too: electrically non-conductive, so spills are harmless. Its price falls between the TF7 and the MX-6, based on our last check.

Key dimensions & specs

  • Amount: 4g
  • Electrically non-conductive: Yes
  • Application: Cannot be spread by hand; cooler pressure distributes it

Pros

  • 4g is enough for several applications
  • Electrically non-conductive, so spills are harmless
  • Dense, high-filler formula
  • Resistance to pump-out, dry-out and bleeding

Cons

  • Costs more than the TF7 at the time of writing
ARCTIC MX-6 (4g)

Best Value2 of 7

ARCTIC MX-6 (4g) on Amazon (opens in a new tab)

MX-6 is the dependable all-rounder: 4g of non-conductive paste that Arctic says beats MX-4, with a consistency suited to bare GPU dies.

Best for

Regular builders and GPU repasting.

Skip if

Price-first buyers should look at the TF7, which cost less when we checked.

Why we like it

It is the value choice for regular use. It matches the MX-7 on tube size (4g). You also get lower thermal resistance than ARCTIC's MX-4, by the maker's measure and a viscosity suited to direct-die GPU use.

Clean off old paste with isopropyl alcohol first, then apply a pea-sized dot or a thin line on the heatspreader; on large Intel chips an X or a line covers the longer die better. Another plus is 4g is enough for several applications. On price it sat third of 7, between the cheaper MX-7 and the pricier Kryonaut, at the time of writing.

Key dimensions & specs

  • Amount: 4g
  • Electrically non-conductive: Yes

Pros

  • 4g is enough for several applications
  • Electrically non-conductive, so spills are harmless
  • Lower thermal resistance than ARCTIC's MX-4, by the maker's measure
  • Viscosity suited to direct-die GPU use

Cons

  • Costs more than the TF7 at the time of writing
Thermal Grizzly Duronaut (2g)

Solid Alternative3 of 7

Thermal Grizzly Duronaut (2g) on Amazon (opens in a new tab)

Duronaut is Thermal Grizzly's long-life paste, built to minimise pump-out and sold with a spatula.

Best for

Buyers who want electrically non-conductive, so spills are harmless.

Skip if

Price-first buyers should look at the TF7, which cost less when we checked.

Why we like it

It suits high-power CPUs that run hot for hours. On tube size it ties with the TF7 at 2g. No other pick in this guide offers an a TG Spatula Pro in the box; compare the NT-H2, which has a three cleaning wipes in the box.

It also comes with aluminium microparticles and zinc oxide nanoparticles. Clean off old paste with isopropyl alcohol first, then apply a pea-sized dot or a thin line on the heatspreader; on large Intel chips an X or a line covers the longer die better. When we checked, only the Kryonaut and cheaper picks cost less, and the NT-H2 cost more.

Key dimensions & specs

  • Amount: 2g
  • Electrically non-conductive: Yes
  • In the box: a TG Spatula Pro

Pros

  • Electrically non-conductive, so spills are harmless
  • Includes a TG Spatula Pro
  • Aluminium microparticles and zinc oxide nanoparticles
  • Formula built to minimise pump-out

Cons

  • Costs more than the TF7 at the time of writing
Noctua NT-H2 (3.5g)

Easiest to Apply4 of 7

Noctua NT-H2 (3.5g) on Amazon (opens in a new tab)

NT-H2 comes with three cleaning wipes and needs no spreading.

Best for

First-time builders.

Skip if

Skip it if price comes first: the TF7 cost less when we checked.

Why we like it

Noctua rates it for up to five years on the CPU, which suits builders who set it and forget it. On tube size it sits mid-pack at 3.5g: the MX-7 comes in at 4g, and the Kryonaut comes in at 1g. It is the only pick here with a three cleaning wipes in the box; the Duronaut has an a TG Spatula Pro in the box instead.

It also comes with a recommended usage time of up to five years on the CPU and enough for around 3 to 20 applications. Clean off old paste with isopropyl alcohol first, then apply a pea-sized dot or a thin line on the heatspreader; on large Intel chips an X or a line covers the longer die better. Do not pre-spread it; let the cooler's mounting pressure distribute it. It was priced above the Duronaut and below the XTM70 at the time of writing.

Key dimensions & specs

  • Amount: 3.5g
  • In the box: three cleaning wipes
  • Application: No need to spread before mounting

Pros

  • Includes three cleaning wipes
  • Recommended usage time of up to five years on the CPU
  • Enough for around 3 to 20 applications
  • Tube size of 3.5g, ahead of the XTM70

Cons

  • Costs more than the TF7 at the time of writing
Thermal Grizzly Kryonaut (1g)

Best Small Tube5 of 7

Thermal Grizzly Kryonaut (1g) on Amazon (opens in a new tab)

Kryonaut is the long-standing enthusiast paste, sold here as a 1g syringe with a spatula.

Best for

A single build or remount.

Skip if

Worth skipping when 1g covers only a couple of large CPU is a problem.

Why we like it

It is enough for one or two large CPUs. Its 1g tube size is the smallest in this group; the MX-7 leads at 4g. You get an a syringe and spatula in the box here, which sets it apart from the NT-H2 and its a three cleaning wipes in the box.

It also comes with a maker claim that it does not dry out at 80°C. Clean off old paste with isopropyl alcohol first, then apply a pea-sized dot or a thin line on the heatspreader; on large Intel chips an X or a line covers the longer die better.

Key dimensions & specs

  • Amount: 1g
  • In the box: a syringe and spatula

Pros

  • Includes a syringe and spatula
  • Maker claim that it does not dry out at 80°C
  • A 1g syringe with spatula

Cons

  • 1g covers only a couple of large CPUs
  • Tube size trails the MX-7 (4g)
  • Costs more than the TF7 at the time of writing
Thermalright TF7 (2g)

Worth Considering6 of 7

Thermalright TF7 (2g) on Amazon (opens in a new tab)

TF7 offers 12.8 W/mK and a wide temperature range in a non-conductive formula.

Best for

Buyers who want maker-rated 12.8 w/mk conductivity.

Skip if

Choose another pick if you can't accept this: tube size of 2g, behind the MX-7 (4g).

Why we like it

It is a low-cost option for a CPU or GPU repaste. It matches the Duronaut on tube size (2g). Clean off old paste with isopropyl alcohol first, then apply a pea-sized dot or a thin line on the heatspreader; on large Intel chips an X or a line covers the longer die better.

Another plus is maker-rated 12.8 W/mK conductivity. It also brings electrically non-conductive, so spills are harmless. It was the cheapest of the group when we checked; the MX-7 was the next step up. The main gap: tube size of 2g, behind the MX-7 (4g). If that matters, the MX-7 comes in at 4g.

Key dimensions & specs

  • Amount: 2g
  • Conductivity: 12.8 W/mK (maker's figure)
  • Electrically non-conductive: Yes

Pros

  • Maker-rated 12.8 W/mK conductivity
  • Electrically non-conductive, so spills are harmless
  • Rated range of -150°C to 250°C
  • Tube size of 2g, ahead of the Kryonaut

Cons

  • Tube size of 2g, behind the MX-7 (4g)
Corsair XTM70 (3g)

Well-Rounded Choice7 of 7

Corsair XTM70 (3g) on Amazon (opens in a new tab)

XTM70 includes an applicator kit and three wipes, with a low viscosity that spreads easily.

Best for

Buyers who want includes an applicator kit and three cleaning wipes.

Skip if

Skip it if price comes first: the TF7 cost less when we checked.

Why we like it

Corsair rates it for CPUs up to 250W and beyond. Corsair rates it for processors up to 250W TDP and beyond, and the kit includes an applicator and three cleaning wipes. Its low viscosity spreads evenly without much effort.

The 3g tube holds enough for several CPU applications. Its 3g tube size ranks fourth of 7 here, behind the MX-7 (4g) and ahead of the Kryonaut (1g). Clean off old paste with isopropyl alcohol first, then apply a pea-sized dot or a thin line on the heatspreader; on large Intel chips an X or a line covers the longer die better. It was the most expensive pick when we checked, so weigh what it adds over the NT-H2.

Key dimensions & specs

  • Amount: 3g
  • In the box: an applicator kit and three cleaning wipes

Pros

  • Includes an applicator kit and three cleaning wipes
  • Low-viscosity formula
  • Rating for processors up to 250W TDP and beyond
  • Tube size of 3g, ahead of the Duronaut

Cons

  • Costs more than the TF7 at the time of writing

How We Chose These Thermal Pastes

Each pick was assessed across 4 criteria weighted for real-world use.

Safety
We checked that each paste is listed as electrically non-conductive.
Value
We compared tube sizes and what comes in the box.
Application
We noted spreaders, wipes and the maker's application guidance.
Durability
We looked for maker claims on pump-out and long-term stability.

What to Look for in a Thermal Paste

Key buying criteria so you get the right fit the first time.

  1. Differences between good pastes are small

    Among reputable pastes, temperatures usually differ by a few degrees at most. Mounting pressure and application matter as much as the paste.

  2. Durability matters on hot CPUs

    Some pastes pump out or dry over thermal cycles. Pastes built for long-term stability suit high-power CPUs you do not want to remount often.

  3. Check the rated service life

    Some makers state how long the paste can stay on a CPU before it needs replacing, from about five years to eight. A longer rating suits a PC you won't open often.

  4. Thicker pastes are harder to spread

    High-performance pastes are often thick. Warming the tube in your hand makes them easier to apply.

  5. Choose non-conductive paste

    Non-conductive pastes are safe if a little spills onto nearby parts. Avoid liquid metal unless you know the risks.

  6. Kits save a trip to the drawer

    Wipes, a spatula or an applicator card make a repaste cleaner. They matter most for a first build or for repasting a graphics card.

How to Choose a Thermal Paste

By priority

PriorityConsiderWhy
Hot CPUs you do not want to repasteMX-7A formula built against pump-out and dry-out
Regular builders and GPU repastingMX-64g of non-conductive paste suited to direct-die use
First-time buildersNT-H2No spreading needed, with three wipes included
A single build or remountKryonautA 1g syringe with spatula

Scroll sideways to see every column.

Key specs side by side

Figures as each maker states them.

PasteAmountElectrically non-conductiveIn the boxApplication
MX-74gYesNot listedCannot be spread by hand; cooler pressure distributes it
MX-64gYesNot listedNot listed
Duronaut2gYesa TG Spatula ProNot listed
NT-H23.5gNot listedthree cleaning wipesNo need to spread before mounting
Kryonaut1gNot listeda syringe and spatulaNot listed
TF72gYesNot listedNot listed
XTM703gNot listedan applicator kit and three cleaning wipesNot listed

Scroll sideways to see every column.

Frequently Asked Questions

Is a higher W/mK rating always better?

Not reliably. Makers test conductivity differently, so the figures are not directly comparable between brands.

Is the paste that comes with my cooler good enough?

Usually yes. Aftermarket paste helps most when remounting or when the included paste has run out.

How do I remove old paste?

Wipe it off with a lint-free cloth and 90% or stronger isopropyl alcohol, then let it dry.

Can a thermal pad replace paste on a CPU?

Phase-change pads such as PTM7950 can, but ordinary gap-filling pads are too thick for a CPU heatspreader and run hotter.

Should I use liquid metal instead?

Only if you know the risks. It is electrically conductive and damages aluminium, so it is not a drop-in replacement.

How often should I replace thermal paste?

Only when you remove the cooler or temperatures rise over time. Many pastes last several years on a desktop CPU.

Bottom Line

Arctic MX-7 is the pick for durability on hot CPUs, and MX-6 is the best value for regular builds and GPU repasting. Thermal Grizzly Duronaut is the other long-life option.

Noctua NT-H2 is the easiest to apply, Kryonaut suits a single build, and Thermalright TF7 and Corsair XTM70 are low-cost alternatives.