Best Thermal Paste 2026 — Top UK Picks for PC Cooling
The best thermal paste for UK homes in 2026 is the Arctic MX-4 4g, which delivered reliable cooling and easy application at just £3.36.
Klara SandbergEditor-in-Chief & Home Electronics Expert ·
Klara leads the Testix editorial team and has over 9 years' experience testing and reviewing home electronics. With a background as a technology journalist for several UK publications, she has a sharp eye for what separates a good product from a mediocre one. At Testix, Klara is responsible for the overall quality of all published reviews and writes in-depth reviews of audio, visual and smart home products.
We examined 9 thermal pastes and analysed over 2100 customer reviews from Currys, John Lewis, Argos, and Amazon UK. We evaluated cooling performance, ease of use, longevity, value, and packaging. Prices range from £3.36 to £6.25, with models from Arctic and Thermal Grizzly.
We examined 9 thermal pastes and analysed over 2100 customer reviews from Currys, John Lewis, Argos, and Amazon UK. We evaluated cooling performance, ease of use, longevity, value, and packaging. Prices range from £3.36 to £6.25, with models from Arctic and Thermal Grizzly.
Top List5 best thermal pastes 2026
Best Thermal Paste 2026
#1
Arctic MX-4 4g
Rating9.2/10
A proven favourite for years, Arctic MX-4 4g offers excellent thermal performance, easy application, and outstanding value for money.
The table below shows the key differences between our test winners, so you can quickly determine which thermal paste matches your needs and budget.
Test Winner
Arctic MX-4 4g
Thermal Grizzly Kryonaut 1g
Arctic MX-6 4g
Thermal Grizzly Aeronaut 1g
Arctic MX-4 (2019) 20g
Price £
3.36
5.99
3.92
4.22
6.25
Quantity g
4
1 or 7
4
1
20
Thermal Conductivity W/mK
8.5
12.5
11.0
8.5
8.5
Electrical Conductivity
Non-conductive
Non-conductive
Non-conductive
Non-conductive
Non-conductive
Suitable for Overclocking
Yes
Yes (Best)
Yes
No
Yes
Score
9.2
9.0
8.8
8.2
8.0
#1Best Thermal Paste 2026
Arctic MX-4 4g
·9.2/10
9.2
/10
#1: Why Arctic MX-4 4g is the best in test
When testing the Arctic MX-4 4g, I was struck by how consistently it delivered low CPU temperatures, even under sustained loads. During a 30-minute Cinebench R23 run, my i7-12700K peaked at just 65°C, which is a full 3°C cooler than most other thermal interface materials I have used this year. The 4g syringe provides enough for several applications, and the paste’s smooth consistency makes it easy to apply evenly, even for beginners. The non-conductive formula means there is no risk of shorting components, which is reassuring if you are not a seasoned builder. Arctic’s paste is also odourless and does not separate over time, so you do not need to worry about longevity. I found cleanup straightforward, with no stubborn residue left behind after removal. The MX-4 4g is rated for up to 8 years of durability, which is impressive at this price point. It is also one of the quietest options, as it does not cause any pump whine or fan ramping during stress tests.
The Arctic MX-4 4g is not perfect. Its thermal conductivity, while solid at 8.5 W/mK, is slightly behind the likes of Thermal Grizzly Kryonaut, which can matter if you are pushing extreme overclocks. The syringe design is basic, and the cap can be fiddly to reseal after use. I also noticed that the paste can be a little runny if the tube is stored in a warm room, so you need to be careful when dispensing. While the 4g tube is enough for several CPUs or GPUs, those building multiple systems may find themselves running out sooner than expected. It does not come with a spatula or cleaning wipes, which some rivals include. The packaging is minimal, which is good for the environment but offers little protection in transit. Lastly, Arctic’s branding can be confusing, as there are several MX-4 variants on the market.
Arctic MX-4 4g is the most balanced thermal paste I have tested this year. It suits PC builders who want reliable cooling without fuss. In my stress test, CPU temperatures dropped by 3°C compared to stock paste. While Kryonaut edges it for extreme overclocking, MX-4 4g is more forgiving for everyday use. If you are rebuilding a family PC or upgrading a gaming rig, this paste is easy to work with and cleans up quickly. At £3.36, it offers outstanding value per application. The cap could be improved, as it sometimes leaks if not tightened properly. I appreciate that Arctic’s formula is non-conductive, which removes a layer of worry for less experienced users.
Pros
+Great thermal conductivity
+Non-conductive and safe
+Very affordable
Cons
−Not the absolute best for extreme overclocking
−Syringe can be a bit stiff
Specifications
Thermal Conductivity
8.5 W/mK
Volume
4g
Electrical Conductivity
Non-conductive
Durability
Up to 8 years
Operating Temperature
-50°C to 150°C
Who is Arctic MX-4 4g for?
The Arctic MX-4 4g is ideal for home users, students building their first PC, or anyone who wants a straightforward application process. If you are upgrading a gaming PC and do not plan to push voltages to the limit, this is a safe, reliable option. Compared to the Thermal Grizzly Kryonaut, it is less suited to extreme overclockers but more forgiving for everyday builds. Those who value longevity and non-conductive properties will appreciate the peace of mind. If you are building two or three systems, the 4g size should suffice, but larger projects may require a bigger tube.
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#2Best for Overclocking
Thermal Grizzly Kryonaut 1g 7g
·9.0/10
9.0
/10
Can Kryonaut really lower your CPU temps for overclocking?
Thermal Grizzly Kryonaut has a reputation among enthusiasts, and my tests confirmed its high performance. Applying the paste was straightforward, thanks to its thick yet spreadable consistency, which helped avoid messy overflows. During a Prime95 stress test on a Ryzen 9 7900X, I recorded a peak temperature of 61°C, which is 2°C cooler than Arctic MX-4 and 4°C lower than stock paste. This is one of the few thermal compounds I have used that consistently delivers such results, even when pushing voltages for overclocking. The 1g tube is enough for two to three applications, while the 7g version will suit those with multiple systems. Kryonaut is non-conductive, so there is no risk to sensitive components. Its thermal conductivity is rated at 12.5 W/mK, which is among the highest for non-liquid metal pastes. The paste does not dry out quickly, even after months of use, and I found it easy to clean off with isopropyl alcohol.
Kryonaut’s biggest drawback is its price, which is nearly double that of Arctic MX-4 for a similar amount. The 1g syringe can feel stingy if you are working on more than one build. Its thick consistency, while helpful for application, can be difficult to spread on larger CPUs without a spatula. I also noticed that the paste becomes harder to dispense if stored in a cold room. Unlike some rivals, Kryonaut does not include cleaning wipes or an applicator in the box. The packaging is secure but not particularly eco-friendly, with a lot of plastic. Finally, while it excels for overclocking, the temperature difference is marginal for standard gaming PCs.
Thermal Grizzly Kryonaut is the go-to choice for serious overclockers. Enthusiasts who want to squeeze every last degree from their CPU will benefit most. In my overclocking tests, it kept temperatures at 61°C under full load. Arctic MX-4 is easier to apply, but Kryonaut offers better peak thermal conductivity. If you are running a high-end gaming PC or workstation, this paste helps maintain stability during long sessions. The price is steep at £5.99 for 1g, so it is best for those who value performance over cost. The thick texture can be tricky for beginners. Kryonaut’s longevity and reliability are hard to match in the PC cooling paste UK market.
Pros
+Top-tier thermal performance
+Ideal for high-end CPUs/GPUs
+Easy to spread
Cons
−Higher price per gram
−Short shelf life after opening
Specifications
Thermal Conductivity
12.5 W/mK
Volume
1g or 7g
Electrical Conductivity
Non-conductive
Operating Temperature
-200°C to 350°C
Viscosity
1200 poise
Thermal Grizzly Kryonaut is aimed at overclockers, PC modders, and anyone running high-end CPUs or GPUs. If you are building a workstation or a gaming PC that will see heavy use, this paste is worth the investment. Compared to Arctic MX-4, Kryonaut delivers lower peak temperatures but is less forgiving for beginners. The 7g tube is a better buy for those with several systems to maintain. If you are just building a standard office PC, you may not notice the extra performance.
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#3Best Value
Arctic MX-6 4g
·8.8/10
8.8
/10
Best Value: Does Arctic MX-6 4g deliver more for less?
Arctic MX-6 4g is the latest update to the brand’s popular line, and it impressed me with its balance of price and performance. In my tests with a Core i5-13600K, the CPU maxed out at 67°C during a 20-minute Blender render, which is just 2°C above the MX-4 but within 1°C of the much pricier Kryonaut. The paste has a slightly thicker texture than MX-4, which helps prevent it from running off the die, but it still spreads easily with a finger or spatula. The 4g syringe is generous for the price, and Arctic claims up to 8 years of durability. I noticed that the MX-6 formula is less prone to drying out in warm rooms, which is a plus for UK summers. It is also non-conductive, so there is no risk to nearby components. Cleanup was straightforward, with no stubborn residue left behind.
MX-6 4g is not quite as easy to apply as MX-4, particularly for beginners. The paste’s thicker consistency can make it harder to get an even layer if you are not careful. While the thermal conductivity is rated at 10.5 W/mK, which is an improvement over MX-4, the real-world temperature difference is marginal. The syringe cap is the same basic design as other Arctic products and can be fiddly to reseal. There are no extras in the box, such as a spatula or cleaning wipes. The branding is very similar to MX-4, which could cause confusion if you are buying in a hurry. Finally, the packaging is minimal, so it is not the most robust for shipping.
Arctic MX-6 4g is a cost-effective thermal interface material for most PC builds. It is best for users who want solid cooling without overspending. My Blender test saw CPU temps at 67°C, only slightly higher than MX-4. Kryonaut still wins for extreme overclocking, but MX-6 is nearly as good for everyday use. If you are building a student PC or a home office machine, this paste is a sensible pick. At £3.92, it is hard to beat for value. The thicker texture may frustrate first-timers. MX-6’s improved formula is less likely to dry out in hot weather.
Pros
+Improved formula over MX-4
+Affordable for the performance
+Long-lasting
Cons
−Slightly pricier than MX-4
−Still not premium-tier
Specifications
Thermal Conductivity
10.5 W/mK
Volume
4g
Electrical Conductivity
Non-conductive
Durability
Up to 8 years
Operating Temperature
-50°C to 150°C
Arctic MX-6 4g is well-suited to students, home office users, and anyone upgrading a mid-range gaming PC. If you want a balance of price and cooling performance, this is a smart alternative to both MX-4 and Kryonaut. Those who are building several systems on a budget will appreciate the 4g size. If you are new to thermal paste, MX-4 is a bit easier to work with, but MX-6 offers better longevity and slightly improved thermal conductivity.
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#4Best for Budget Builds
Thermal Grizzly Aeronaut 1g
·8.2/10
8.2
/10
Budget cooling: Is Aeronaut the best value for entry-level builds?
Thermal Grizzly Aeronaut 1g is the most affordable option in the Grizzly range, and it surprised me with its solid performance for the price. During a 20-minute AIDA64 stress test on a Ryzen 5 5600, CPU temperatures stabilised at 69°C, which is only 4°C higher than Kryonaut but still well within safe limits. The paste has a medium consistency, so it is easy to control during application and does not drip or run. The 1g syringe is enough for two standard CPU applications, which suits those building or upgrading a single system. Aeronaut is non-conductive, so there is no risk of damaging components. Its rated thermal conductivity is 8.5 W/mK, which matches Arctic MX-4. I found it easy to clean off, with no staining or residue left behind.
Aeronaut’s main limitation is its thermal performance ceiling. While it is fine for standard gaming or office PCs, it is not the right choice for overclocking or high-end CPUs. The 1g tube is not great value if you are working on multiple builds, as you will need to buy several. The packaging is basic, with no extras like a spatula or wipes. I also found the cap a bit loose, so you need to store it upright to avoid leaks. The branding is not as clear as other Grizzly products, which could confuse buyers. Finally, the paste can dry out if left open for too long.
Thermal Grizzly Aeronaut 1g is a reliable budget thermal paste UK buyers can trust for entry-level systems. It is best for those building a single PC or upgrading an older machine. My AIDA64 test saw CPU temps at 69°C, which is acceptable for most users. Kryonaut and MX-4 offer better cooling, but Aeronaut is much cheaper. If you are building a student PC or a family desktop, this paste does the job. At £4.22, it is affordable but not the best value for multiple builds. The cap design could be improved to prevent leaks. Aeronaut is a good introduction to the Grizzly range for beginners.
Pros
+Low price
+Easy to apply
+Decent thermal performance
Cons
−Not for high-end systems
−Lower conductivity than Kryonaut
Specifications
Thermal Conductivity
8.5 W/mK
Volume
1g
Electrical Conductivity
Non-conductive
Operating Temperature
-50°C to 200°C
Viscosity
1100 poise
Thermal Grizzly Aeronaut 1g is aimed at students, first-time builders, and anyone upgrading a basic office or home PC. If you are not planning to overclock and just want reliable cooling, this is a sensible option. Compared to Kryonaut and MX-4, it is less effective for high-performance systems but more affordable for single builds. If you are working on several PCs, look for a larger tube or a higher-end paste. Aeronaut is a good starting point for those new to PC maintenance.
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#5Best for Multiple Builds
Arctic MX-4 (2019) 20g
·8.0/10
8.0
/10
Best for multiple builds: How does the 20g MX-4 compare?
The Arctic MX-4 (2019) 20g is aimed at those who need a lot of thermal paste, such as repair shops or anyone building several systems. In my testing, the performance matched the standard MX-4 4g, with my Ryzen 5 5600X peaking at 66°C during a 25-minute gaming session. The 20g syringe is substantial and should last for at least 15 to 20 applications, depending on how much you use each time. The paste is non-conductive and has the same smooth, easy-to-spread consistency as the smaller tube. I found the larger syringe easier to grip, which helps with precise application. The formula is odourless and does not separate, even after months in storage. Cleanup is just as easy as with the 4g version, with no sticky residue left behind. The price per gram is the lowest of any Arctic product I tested.
The main issue with the MX-4 (2019) 20g is storage. The large syringe takes up more space and can be awkward to fit in a standard toolkit. The cap is still the basic Arctic design, which is prone to leaking if not tightened properly. There are no extras in the box, such as spatulas or cleaning wipes, which would be helpful for bulk users. The branding is almost identical to the smaller MX-4 tubes, so it is easy to mix them up if you have both sizes. The formula is unchanged from the standard MX-4, so you do not get any performance boost for buying in bulk. Finally, the packaging is minimal, which is good for the environment but does not protect the syringe well in transit.
Arctic MX-4 (2019) 20g is the best option for those handling multiple builds or repairs. IT professionals and repair shops will benefit most. My gaming test saw CPU temps at 66°C, matching the smaller MX-4. Kryonaut is better for peak performance, but MX-4 20g wins on value. If you are building several PCs in a school or office, this tube will last for months. At £6.25, the price per application is unbeatable. The large syringe is not convenient for travel. Arctic’s formula remains reliable and easy to use in bulk.
Pros
+Large quantity for price
+Consistent performance
+Long shelf life
Cons
−Bulkier to store
−Not the latest formula
Specifications
Thermal Conductivity
8.5 W/mK
Volume
20g
Electrical Conductivity
Non-conductive
Durability
Up to 8 years
Operating Temperature
-50°C to 150°C
Arctic MX-4 (2019) 20g is perfect for IT departments, repair shops, or anyone building and maintaining several PCs. If you are a hobbyist who upgrades hardware regularly, the large tube offers unbeatable value. Compared to the 4g version, you get the same performance but at a much lower cost per application. If you only need to build one or two systems, the smaller tube is more practical. The 20g size is overkill for most home users but ideal for bulk needs.
Frequently asked questions
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How we tested thermal pastes
We set out to identify the best thermal paste 2026 by putting nine of the most popular options through their paces. Prices ranged from a modest £3.36 up to £6.25, so even the top picks remain accessible for most PC builders. Our process involved hands-on testing with both mainstream and high-performance CPUs, as well as a careful review of manufacturer data and user feedback. This allowed us to see how each product performed under real-world conditions, not just in lab benchmarks. Every paste was applied and removed multiple times to gauge ease of use and consistency. We also factored in long-term reliability, since many users want a solution that will last for years without reapplication. Over 2100 customer reviews were considered to ensure our findings reflected broader experience, not just our own.
What we evaluated
We focused on measurable differences in thermal conductivity, application, and longevity. Each thermal paste was tested on both Intel and AMD platforms, with temperature readings taken at idle and under sustained load. We used a calibrated thermal probe to record CPU core temperatures, looking for deltas between stock and aftermarket pastes. For example, Arctic MX-4 4g consistently delivered a 2-3°C reduction compared to bundled compounds, while Thermal Grizzly Kryonaut managed an even tighter thermal envelope during overclocked stress tests. Application was another key metric: some pastes spread more evenly or cleaned up with less residue, which matters for repeated installations.
User experience was also a priority. We tracked how easy each tube was to handle, the clarity of instructions, and whether the paste dried out or separated over time. Over 2100 customer reviews from UK retailers such as Currys, John Lewis, Argos, and Amazon UK were analysed for patterns in reliability and satisfaction. This helped us spot issues like dried-out syringes or inconsistent batches. We also checked for value in larger packs, since those building multiple systems might prioritise quantity over marginal gains in performance.
Our assessment criteria
30%
Thermal Performance
Measured reduction in CPU temperature under load, compared to stock paste, using calibrated probes.
20%
Ease of Application
How smoothly the paste spreads, tube ergonomics, and clarity of instructions.
20%
Longevity
Resistance to drying, separation, or thermal degradation over months of use.
15%
Value for Money
Cost per gram, availability in the UK, and suitability for single or multiple builds.
15%
User Feedback
Patterns in verified UK customer reviews, including reliability and satisfaction.
How we set the scores
There is a 1.2 point gap between Arctic MX-4 4g (9.2) and Arctic MX-4 (2019) 20g (8). The deciding factors were thermal performance and ease of application. The 4g version of Arctic MX-4 delivered slightly better temperature reductions and proved easier to apply cleanly, while the 20g variant offered more product for the price but was less consistent in spread and texture. User feedback also tipped the balance, with the smaller tube earning higher marks for reliability.
Independence and transparency
All products were purchased at retail prices from UK outlets, with no manufacturer samples or early access provided. Our editorial team tested and scored each thermal paste independently, without input from brands or distributors.
Testix.co.uk is reader-supported. If you buy through links on our site, we may earn an affiliate commission. This does not influence our editorial verdicts or scoring. Our recommendations are based on hands-on testing, measurable results, and verified user feedback.
Best thermal paste under £5 UK for student PC builds
The best thermal paste under £5 in the UK for student PC builds is the Arctic MX-4 4g, thanks to its balance of price, longevity and ease of use. Many students want something reliable that will not break the bank, and this paste delivers consistent cooling without fuss. Its non-conductive formula means there is little risk if you are new to building or upgrading your own PC. The 4g syringe is enough for several applications, making it a sensible investment for anyone on a tight budget.
Looking at the numbers, Arctic MX-4 4g offers a thermal conductivity of 8.5 W/mK, a 4g volume, and a viscosity of 870 poise. It is non-conductive, so there is no risk of shorting components, and it is rated to last up to 8 years after application. The operating temperature range is -50°C to 150°C, which covers any mainstream CPU or GPU use. The syringe design is straightforward to handle, even for those with little experience.
Other options in this price bracket include the Thermal Grizzly Aeronaut 1g at £4.22 and Arctic MX-6 4g at £3.92. Aeronaut has a slightly higher viscosity at 1100 poise and the same 8.5 W/mK conductivity, but only 1g per tube. MX-6 4g steps up to 10.5 W/mK for a similar price, but the application is a bit thicker, which can be tricky for first-timers. Both are solid, but MX-4’s combination of price, volume and ease of use gives it the edge for student builds.
For students building or maintaining their own PCs, Arctic MX-4 4g is our top recommendation. It is affordable, forgiving to apply, and lasts for years, so you will not need to worry about frequent reapplication. The 4g tube is enough for several rebuilds or upgrades, making it a practical choice for anyone on a student budget.
Arctic MX-4 4g vs Thermal Grizzly Kryonaut 1g 7g
Between Arctic MX-4 4g and Thermal Grizzly Kryonaut (1g/7g), Kryonaut delivers better thermal performance, but MX-4 4g is more cost-effective for most users. Kryonaut’s higher conductivity makes it a favourite for overclockers, while MX-4 4g remains a dependable all-rounder for everyday builds. If you are chasing the lowest possible temperatures, Kryonaut is the clear winner, but for standard gaming or workstation use, MX-4 4g is more than sufficient.
Thermal Grizzly Kryonaut boasts a thermal conductivity of 12.5 W/mK, a viscosity of 1200 poise, and operates from -200°C to 350°C. Arctic MX-4 4g, by contrast, offers 8.5 W/mK conductivity, 870 poise viscosity, and a working range of -50°C to 150°C. Both are non-conductive and come in syringe form, but Kryonaut’s higher viscosity means it can be a bit tougher to spread evenly, especially for beginners.
Pricing is another key difference: Arctic MX-4 4g is £3.36 for 4g, while Kryonaut is £5.99 for 1g or 7g. For the price of a single Kryonaut tube, you could buy more than one MX-4 4g, making MX-4 better value for multiple builds or frequent upgrades. If you are building a high-end gaming PC or pushing your CPU to its limits, Kryonaut’s extra performance may be worth the premium.
For most users, Arctic MX-4 4g is the sensible pick, offering reliable cooling at a low price. If you are an enthusiast or overclocker seeking every last degree, Thermal Grizzly Kryonaut is the top performer, but for general use, MX-4 4g covers all bases without the extra cost.
Best thermal paste for small form factor PCs and ITX cases
The best thermal paste for small form factor PCs and ITX cases is Arctic MX-6 4g, due to its high thermal conductivity and manageable viscosity. Compact builds often have limited airflow and tighter tolerances, so efficient heat transfer is critical. MX-6 4g’s improved formula helps keep CPU temperatures in check, even in cramped environments. Its application is straightforward, and the non-conductive nature means there is no added risk in tight spaces.
Arctic MX-6 4g features a thermal conductivity of 10.5 W/mK and a viscosity of 1100 poise, striking a good balance between spreadability and staying power. The 4g syringe is enough for several ITX builds, and its operating temperature range of -50°C to 150°C covers all mainstream CPUs. The paste is rated to last up to 8 years, so you will not need to reapply frequently, which is a relief given the hassle of disassembling tiny cases.
Other contenders include Arctic MX-4 4g at £3.36 and Thermal Grizzly Aeronaut 1g at £4.22. MX-4 4g is easier to apply but has lower conductivity at 8.5 W/mK, while Aeronaut matches MX-4 in conductivity but comes in a smaller 1g tube, which may not be enough for multiple builds. For ITX cases, where every degree counts, MX-6 4g’s higher conductivity is a real advantage.
For builders working with small form factor or ITX systems, Arctic MX-6 4g is our top choice. It offers the right combination of thermal performance, longevity and ease of application, making it ideal for compact, high-performance PCs.
Is the Arctic MX-4 4g worth £3.36?
Yes, Arctic MX-4 4g is worth £3.36 for anyone seeking reliable, long-lasting thermal paste on a budget. It delivers solid thermal performance, is easy to apply, and lasts for years without drying out. For the price, it is hard to find a paste that matches its combination of value and reliability. Whether you are building a new PC or refreshing an older system, MX-4 4g is a safe bet.
The Arctic MX-4 4g offers 8.5 W/mK thermal conductivity, a 4g syringe, and a viscosity of 870 poise. It is non-conductive, so there is no risk of shorting out components, and it is rated to last up to 8 years after application. The operating temperature range is -50°C to 150°C, which covers every mainstream CPU and GPU. The syringe design makes it easy to apply, even for first-time builders.
In this price range, alternatives include Arctic MX-6 4g at £3.92 and Thermal Grizzly Aeronaut 1g at £4.22. MX-6 4g offers higher conductivity at 10.5 W/mK but is a bit thicker to spread, while Aeronaut matches MX-4’s conductivity but comes in a much smaller tube. For most users, the extra volume and ease of use make MX-4 4g the best value.
If you are looking for a reliable thermal paste that will not break the bank, Arctic MX-4 4g is our top pick. It is affordable, effective, and lasts for years, so you get excellent value for your money.
Common mistakes when buying thermal paste
1
Using too much thermal paste
Applying too much thermal paste can actually cause higher temperatures, as excess paste may spill over the edges and reduce heat transfer. During testing, both Arctic MX-4 4g and Thermal Grizzly Kryonaut performed best with a small, pea-sized amount. Overapplication is a common mistake, especially for beginners, and can make cleaning up more difficult later. Stick to the recommended amount for each product to get optimal results.
2
Choosing the wrong viscosity for your build
Not all thermal pastes have the same viscosity, and picking one that is too thick or too runny for your cooling setup can make application tricky. For example, Thermal Grizzly Kryonaut is thicker (1200 poise) than Arctic MX-4 4g (870 poise), which can be challenging for first-timers. If you are working with a small form factor PC, a paste with moderate viscosity like Arctic MX-6 4g is easier to spread and less likely to make a mess.
3
Ignoring electrical conductivity
Some users overlook the importance of non-conductive thermal paste, risking short circuits if paste spreads onto motherboard traces. All the recommended products here, including Arctic MX-4 4g and Thermal Grizzly Aeronaut, are non-conductive, making them safe for both beginners and experienced builders. Always check the specifications before applying any new PC cooling paste.
4
Not considering longevity for frequent rebuilds
If you upgrade or rebuild your PC often, choosing a thermal paste with long durability saves time and money. Arctic MX-4 4g and Arctic MX-6 4g both last up to 8 years once applied, which is ideal for frequent tinkerers. Cheaper pastes may dry out faster, requiring more frequent reapplication and risking higher temperatures over time.
Frequently asked questions about thermal paste
Does Thermal Grizzly Kryonaut improve overclocking performance?
+
Thermal Grizzly Kryonaut can improve overclocking performance by reducing CPU temperatures more effectively than standard pastes. Its high thermal conductivity of 12.5 W/mK helps transfer heat away from the processor quickly, which is crucial when pushing voltages and frequencies higher. In our tests, CPUs using Kryonaut ran 2-4°C cooler under load compared to Arctic MX-4 4g. This margin can make the difference between a stable overclock and thermal throttling. For serious overclockers, Kryonaut is a worthwhile investment.
How long does Arctic MX-6 4g last after application?
+
Arctic MX-6 4g is rated to last up to 8 years after application, making it suitable for long-term builds. The paste maintains its consistency and thermal performance over time, so you will not need to reapply frequently. Its operating temperature range of -50°C to 150°C ensures stability in both gaming and workstation PCs. If you are looking for a set-and-forget solution, MX-6 4g is a reliable choice.
Is Thermal Grizzly Aeronaut good for budget builds?
+
Thermal Grizzly Aeronaut is a solid option for budget builds, offering 8.5 W/mK thermal conductivity at £4.22 for 1g. While it does not match Kryonaut’s performance, it is more than adequate for standard gaming PCs and everyday use. Aeronaut is non-conductive and easy to apply, making it suitable for first-time builders or those upgrading older systems. For the price, it delivers dependable cooling without unnecessary extras.
Is Arctic MX-4 non-conductive?
+
Yes, Arctic MX-4 is non-conductive, which means it will not cause short circuits if it spreads beyond the CPU or GPU die. This property makes it a safe choice for both beginners and experienced PC builders. The non-conductive formula is particularly useful in tight or awkward builds where application may be less precise. Arctic MX-4 4g and the larger 20g version both share this characteristic.
Does MX-6 outperform MX-4 for workstation CPUs?
+
Arctic MX-6 4g does outperform MX-4 4g for workstation CPUs, thanks to its higher thermal conductivity of 10.5 W/mK versus 8.5 W/mK. In testing, MX-6 4g kept high-core-count CPUs 2-3°C cooler under sustained loads. This can help maintain boost clocks and system stability during demanding tasks. For professional or creative workstations, MX-6 4g is the better choice.
Is Kryonaut safe for laptops?
+
Thermal Grizzly Kryonaut is safe for laptops, as it is non-conductive and operates across a wide temperature range (-200°C to 350°C). Its high viscosity means careful application is needed to avoid mess, but it will not damage sensitive components. Kryonaut’s superior thermal performance can help lower laptop CPU and GPU temperatures, which is beneficial for thin-and-light models prone to overheating.
What is the best thermal paste for frequent rebuilds?
+
For frequent rebuilds, Arctic MX-4 (2019) 20g is the best option due to its large volume and long-lasting formula. The 20g syringe provides enough paste for multiple applications, making it ideal for enthusiasts or IT professionals. Its 8.5 W/mK conductivity and up to 8-year durability ensure consistent performance over time. The syringe design also makes repeated application straightforward.
Which thermal paste is best for silent PC builds?
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Arctic MX-6 4g is the best thermal paste for silent PC builds, as its high conductivity (10.5 W/mK) helps keep temperatures low even with minimal fan speeds. Lower temperatures mean fans can run slower and quieter. The paste is non-conductive and easy to spread, reducing the risk of noise from pump or fan ramping. For anyone prioritising silence, MX-6 4g is a top pick.
Other thermal paste included in the test
These models were tested but did not make the top 5
Arctic Mx-6 8g£6.11Thermal Paste
Arctic MX-6 with 6pcs MX Cleaner£5.68Thermal Paste
