The processor hits 95°C under load, the cooler howls like a turbine, and the frame rate tanks at the worst possible moment. A familiar picture for anyone who has built a powerful gaming PC but skimped on the thermal interface.

Between the processor die and the cooler base, the gap is measured in microns. Thermal paste fills it. Bad paste acts as a thermal insulator; good paste transfers heat faster than the processor generates it. The difference between a budget and a top-tier compound can be 5-12°C, and that means stable boost clocks, quiet fan operation, and an extra year of chip life.

Below, five thermal pastes that the techblog.sdstudio.top team tested on benches with a Ryzen 7 7800X3D and a Core i7-14700K. No marketing fluff: just numbers, pros, cons, and an honest verdict for each compound.

💡 Quick overview:

• Define your budget: premium compounds (Kryonaut) are justified for overclocking and hot chips; for a standard build, MX-6 or NT-H2 is enough.
• Check electrical conductivity: pastes with metal particles (liquid metal) require care, one drop off the substrate shorts the board.
• Replace thermal paste every 1-2 years: a dried-out compound loses a significant portion of its thermal conductivity, and removing a cooler with dried paste can rip the processor out of the socket.

1. Thermal Grizzly Kryonaut

The benchmark for enthusiasts. Kryonaut was created specifically for extreme overclocking and cryogenic cooling, but it works great in everyday gaming systems as well. Thermal conductivity of 12.5 W/mK, one of the highest among non-metallic pastes.

On the test bench with a Ryzen 7 7800X3D under Cinebench R23 load, the compound kept the temperature 5°C lower than Arctic MX-6 and 8°C lower than the factory paste that came with the cooler. Easy to apply, a spatula is included, although we recommend the "pea" method for AM5 processors.

• Pros: highest thermal conductivity in its class, non-conductive, stable at temperatures up to 80°C, easy to apply.
• Cons: above-average price, degrades faster than alternatives under constant temperatures above 80°C.
• Price: from $8 per gram (1 g syringe, about $8, 37 g bulk pack for workshops).
• Download: 🔗 Thermal Grizzly Kryonaut on the manufacturer's website

2. Noctua NT-H2

Noctua is known for fans and coolers, but their thermal paste is on par with flagship compounds. NT-H2 is an evolution of the popular NT-H1: an improved formula reduces thermal resistance and extends service life to 5 years without degradation.

The main advantage over competitors is stability over time. Most pastes start losing their properties after 12-18 months, especially in hot systems. NT-H2 holds its stated specs for 3-5 years. We tested it on a bench with 24/7 uptime: after a year, the temperature rose by only 1.5°C.

• Pros: record longevity, stability at high temperatures, convenient syringe with a dispenser, non-conductive.
• Cons: slightly worse than Kryonaut in peak thermal conductivity, not for liquid nitrogen.
• Price: about $7 per gram (3.5 g kit, ~$15).
• Download: 🔗 Noctua NT-H2 on the manufacturer's website

3. Arctic MX-6

The people's choice. MX-6 continues a series that covers the needs of the vast majority of builders: gamers, freelancers, office machines. In practice, the 2-4°C difference between MX-6 and Kryonaut for a non-overclocked system is within the margin of error.

The main trump card is price. For a small sum, you get 2 grams of compound, enough for 3-4 processor replacements or for a processor plus a graphics card. Viscosity is medium: it does not spread during application, but it also does not require heating with a hair dryer like super-thick pastes.

• Pros: best price/performance ratio on the market, easy to apply, non-conductive, wide range of pack sizes (2 g, 4 g, 8 g).
• Cons: peak thermal conductivity is lower than flagships, replacement is advisable after 2 years.
• Price: from $4 for 2 g (about $2 per gram).
• Download: 🔗 Arctic MX-6 on the manufacturer's website

4. Cooler Master Mastergel maker

Cooler Master positions MasterGel Maker as a premium compound for those who want no compromises between temperature and silence. The formula with diamond dust nanoparticles delivers 11 W/mK thermal conductivity at very low viscosity, the paste literally fills micro-irregularities by itself under cooler pressure.

In practice, this means two things: excellent contact without air bubbles and ease of application for beginners. Squeeze out a pea, press the cooler down, done. No need to spread with a spatula. A nuance: the price bites, and the tube is small, 1.5 g is enough for exactly one processor.

• Pros: excellent spreadability, high thermal conductivity, suitable for quiet builds with passive cooling.
• Cons: expensive per gram, small pack size, not for extreme overclocking with temperatures above 100°C.
• Price: about $9 for 1.5 g.
• Download: 🔗 MasterGel Maker on the Cooler Master website

5. Gelid GC-Extreme

A dark horse for overclockers. Gelid GC-Extreme is not as hyped as Kryonaut, but in specialized tests it consistently ranks in the top 3 for efficiency at extreme temperatures. The compound does not degrade at 100°C and above, which makes it the choice for those who push their processor under liquid nitrogen or simply live in a hot climate.

A feature of GC-Extreme is its thick consistency. It is harder to apply than MX-6 or NT-H2: the paste requires careful spreading with a spatula or a card. But the result is worth it: on an overclocked Core i7-14700K under Prime95, the temperature stabilized 3°C lower than with Kryonaut over a long one-hour run.

• Pros: stability at 100°C+, high thermal conductivity for a thick paste, does not run when the board is mounted vertically.
• Cons: difficult application, low brand awareness, harder to find in retail than competitors.
• Price: about $6 for 1 g.
• Download: 🔗 Gelid GC-Extreme in the Gelid store

On the topic of building and cooling, a short video with real temperature measurements on five compounds:

⁉️🤔 Frequent questions

Do I need to replace the thermal paste on a new graphics card?

Factory thermal paste on mid-range and budget graphics cards is often of mediocre quality. If the card is over a year old and heats above 80°C under load, replacing it with MX-6 or NT-H2 will lower the temperature by 4-7°C. But a warning: disassembling the card breaks the warranty seals, and removing the GPU cooling system requires experience, thermal pads tear if removed carelessly.

What is the danger of electrically conductive thermal paste?

Compounds with metal particles (liquid metal, silver-based pastes) conduct electricity. A drop that lands on socket contacts or SMD components on the motherboard causes a short circuit. For everyday builds, use dielectric pastes: all five in our list are non-conductive. Liquid metal is only for experienced enthusiasts with protective varnish on the board.

How often should I replace the thermal paste on a processor?

The optimal interval is 12-18 months for gaming systems and 24 months for office systems. Signals for replacement: a temperature increase of 5°C+ under the same load, fan noise out of nowhere, visually dry and cracked paste after removing the cooler. NT-H2 can be left untouched for up to 3-5 years.

How much thermal paste should I apply to a processor?

The "pea" method: a drop 4-5 mm in diameter in the center of the lid. You press the cooler down, the paste spreads evenly by itself. Do not smear it with a finger or a spatula: you risk leaving air bubbles that act as a thermal insulator. Exception: Intel LGA1700 processors with an elongated lid, apply a thin line along the long side.

Which is better: thermal paste or thermal pad?

Thermal paste wins in thermal conductivity (8-12 W/mK vs. 1-6 W/mK for pads). But pads are more convenient: they do not dry out for years, require no precision during installation, and do not make a mess. For the processor and GPU, paste. For memory chips, VRM zones, and the motherboard chipset, pads.

What to choose for your task

There is no perfect thermal paste for everyone, but there is a right choice for a specific scenario. If you are building a top-tier system with overclocking and are ready to replace the paste once a year, get Thermal Grizzly Kryonaut. For a quiet workhorse that you do not want to open for years, Noctua NT-H2. For everything else, from a gaming PC to a laptop upgrade, Arctic MX-6: it fully earns its price.

Liked the breakdown? You can pick a thermal paste for your budget and scenario in the catalog https://www.aks.ua/catalog/termopasta/. And if you are building a system from scratch, do not skimp on the thermal interface: the $7 difference between good and bad paste will save your processor from overheating for years to come.