Choosing the best thermal paste may sound simple, but a dizzying array of options can turn this seemingly easy choice into a time-consuming task. Thermal paste is designed to minimize microscopic air gaps and irregularities between the surface of the cooler and the CPU's IHS (integrated heat spreader), the piece of metal which is built into the top of the processor.
Good thermal paste can have a profound impact on your performance, because it will allow your processor to transfer more of its waste heat to your cooler, keeping your processor running cool. Choosing the best thermal paste is also important if you plan on overclocking your rig to its fullest. Even the best CPUs for gaming can often hit slightly higher CPU overclocks if they're paired with a good thermal paste.
Performance enthusiasts often swear by a favorite brand of paste, but new recipes crop up from time to time. We've conducted extensive testing of some of the top thermal pastes on the market, and if you're on the hunt for more exotic pastes that are off the beaten path, we also have plenty of historical data below covering 90 different pastes (and yes, we've even tested toothpaste).
Thermal paste can go by many names, such as "thermal compound," "thermal grease," or "TIM" (Thermal Interface Material). Most pastes are comprised of ceramic or metallic materials suspended within a proprietary binder which allows for easy application and spread as well as simple cleanup.
These thermal pastes can be electrically conductive or non-conductive, depending on their specific formula. Electrically conductive thermal pastes can carry current between two points, meaning that if the paste squeezes out onto other components, it can cause damage to motherboards and CPUs when you switch on the power. A single drop out of place can lead to a dead PC, so extra care is imperative.
Liquid metal compounds are almost always electrically conductive, so while these compounds provide better performance than their paste counterparts, they require more focus and attention during application. They are very hard to remove if you get some in the wrong place, which would fry your system.
In contrast, traditional thermal paste compounds are relatively simple for every experience level. Most, but not all, traditional pastes are electrically non-conductive.
Even though there are a dizzying array of different thermal pastes available — some blends have been around for longer than a decade — new formulations still come to market at a surprising pace. In fact, long-time PC cooler-maker NZXT just entered the market with its first paste, the not-very-excitingly named NZXT High-Performance Thermal Paste. Long-time TIM-maker Cooler Master also just introduced a new purple CryoFuze, and Alphacool also recently introduced its Apex thermal paste. Cooling mainstay Corsair also has a new XTM70 blend that will be heading to our test bench soon, showing that the TIM market is still thriving. Both of these new pastes will make it to our test bench soon, but we have plenty of tested pastes for your perusal.
As new pastes arrive, older pastes also get retired. Arctic will retire its ever-popular MX-5 paste, one of the staples in our recommendations below, as it makes way for the new MX-6 that just launched with claims of up to 20% better performance. We'll keep the MX-5 listed, but be aware that once the existing stock is gone, this favorite will no longer be available. We'll also have MX-6 in for testing soon.
Here are the best thermal pastes, along with our complete test results. Keep in mind that you don't always get what you pay for as some budget pastes come awfully close to or overtake their more-expensive competitors.
Best Premium (Standard) Thermal Paste
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Often hanging close to, but not overtaking, liquid metal compounds in our tests, PromilaTech PK-3 Nano Aluminum paste is a moderately viscous thermal compound integrated with aluminum and zinc oxide. The paste provides good stability, making it easy to apply to all surfaces as well as simple to clean up. You really can't go wrong with this paste — it is sufficient for most CPU applications.
Thermal Grizzly Kryonaut is a mildly viscous thermal compound with good stability, making it simple to work with while also resisting drips and runs. This paste is very easy to apply and clean up, making it a favorite among system builders.
A compound with traditional thermal compound attributes such as thick, pliable viscosity and good stability upon application. MasterGel Pro v2 is easy to work with, simple to apply and cleans up well. Technical spec sheets do not list individual ingredients.
MX-5 is a new compound which does not directly replace their popular MX-4 but is a new formulation for enthusiast use based on carbon micro-particulates in what is assumed to be a silicon or silicone base. The slight-blue tint and smooth, viscous compound has a bit more fluid consistency much like thin toothpaste making it easy to apply and cleanup which lends to very smooth and fast spreading during cooler tension, but can also be prone to dripping and running if applied on vertical surfaces.
This paste is being retired as Arctic brings its new MX-6 to market, so it will only be available until supplies run out.
NB Max Pro is a smooth, creamy non-conductive paste that flows well during tensioning. This paste has a simple application and cleanup paired with a good cost and price/performance per gram.
Best Budget Thermal Paste
Noctua’s NH-H1 is a relatively viscous and stable compound that applies easily and allows for easy clean-up. A screw-on cap syringe maintains compound longevity to prevent drying and is priced as an attractive paste for those on a budget. You really can't go wrong with this paste — it is sufficient for the majority of builds.
Gelid GC-Extreme is a moderately viscous compound, making it very stable during application and it spreads consistently, although it requires slow consistent pressure on the syringe plunger for correct placement. This TIM is relatively easy to use and simple to clean up.
A compound with relatively ‘normal’ viscosity known to thermal paste application as well as good stability during application. While known and listed to being electrically non-conductive, most technical data sheets refer to the chemical make-up which includes heat-conductive metal oxides suspended in what is likely a silicone base.
This thick, viscous non-conductive compound has a great deal of plasticity, giving it slower spreading properties. As a result, heatsink installation will require additional focus to apply even tension to ensure proper spread. The compound’s formula mentions the use of carbon particles in its composition.
The NTE 303A paste is an industrial silicone thermal compound designed for diodes and transistors in commercial and residential electronic equipment. NTE 303A is silky smooth and spreads very easily. The large, 1oz (28.35g) syringe provides an unbelievably low price per gram, so it would be a favorite for system builders or hardware testers who apply compound often.
Best Liquid Metal Thermal Paste
Thermal Grizzly Conductonaut liquid metal thermal compound has a very thin, runny consistency and is applied to the CPU integrated heat spreader with a syringe delivery system and capillary needle applicator tip. Excess material can be siphoned off using a special extraction tip (by pulling the syringe plunger to withdraw excess liquid metal).
CoolLaboratory Liquid Pro is a liquid metal compound that is applied with a syringe and capillary tip to the CPU integrated heat spreader, and it ships with a scouring pad and alcohol swab for prep and cleanup.
Application and spreading of the liquid metal are made easier with cotton swabs and generous pressure for even distribution. Liquid metal can cause reactions with some metals, such as aluminum, and some reports of reactions with copper are also documented by end-users.
Best Budget Liquid Metal Thermal Paste
For a compound that costs less than half as much as leading competitors , Phobya's Liquid Metal Compound LM offers impressive performance, often besting the the CoolLaboratory Liquid Pro or Thermal Grizzly Conductonaut in our tests.
Liquid Metal Compound LM ships as a syringe with a capillary applicator tip. Spreading the compound is made easier with cotton swabs and generous pressure to develop a consistent coating on the CPU IHS. Can cause reactions with aluminum and other metals.
Thermal Paste Performance Rankings
Here's a breakdown of our recent testing, and we'll be adding new pastes to this list over the coming weeks and months. A bit further down, you'll find our original round of testing with 85 different pastes, some of which we've revisited in this new performance hierarchy. That should give you a good idea of how other pastes that we haven't retested yet would compare to the newer pastes.
We'll go into our breakdown of how we test these thermal pastes below, but the key takeaway here is that a single thermal compound can perform differently based upon several variables, such as what type of cooler and mount you use. To cover all the bases, we've tested every thermal paste with three variables:
- Low-tension Noctua NH-D15 mounting to model an air cooler without a backplate (like an Intel stock cooler, or push-pin coolers)
- High-tension Noctua NH-D15 mounting to model higher-end air coolers with a backplate
- High-tension mounting with an all-in-one (AIO) liquid cooler
Below you'll find the temperatures we measured on our standardized test bench, and as always, lower temperatures are better. We've also included value charts in the album below as well.
Thermal Paste Test Results
As shown in the slides above, the outcome of the different testing scenarios resulted in some interesting comparisons among the compounds. We’ll look at the overall thermal load averages for each, as well as the relative performance value of each in terms of price-per-gram.
Air Cooling – Low Tension Mount
Liquid metal compounds make their way to the top of the temperature chart with slightly cooler values than the traditional pastes. Interestingly, the difference between the top and bottom of this chart is less than 4C.
When we look at each compound in terms of unit cost-per-gram, liquid metal compounds are generally more costly, making their overall performance value more of a luxury than a necessity. However, Phobya LM bucks this trend as it shows you can get good liquid metal compound performance at bargain pricing.
Air Cooling – High Tension Mount
Liquid metals are again at the top of the list, and again, there’s a relatively small 4C delta between the top and bottom of the list. Only a few minor changes to the pecking order have occurred, and these easily fall within the tight margins of standard deviation.
Small differences in temperatures jostle the chart a bit, but overall the more budget-friendly compounds show much more promising performance value due to relatively close load ranges. We see a trend that most good and great thermal compounds perform very similarly, but might be worlds apart in price per gram.
All In One (AIO) Liquid Cooler – High Tension Mount
It’s no surprise that the liquid metal compounds once again sit atop the thermal comparison. Still, a 6C difference between all 15 thermal compounds tested shows there isn’t a lot of variation, even with a 360 all-in-one cooler with a push+pull fan setup for performance.
The performance value chart shows most of the liquid metal compounds with a poor value-per-gram rating, but once again, Phobya LM proves to be the outlier for that sub-category with its budget price tag.
We’re also seeing the trend of larger gram-per-package for thermal pastes (2-5g syringes) along with lower price proving to be stiff competition against the more expensive liquid metals (0.5-1.0g syringes) that cost upwards of twice as much, or more.
Thermal compounds might always be compared and debated over, but the simple fact remains: PC system building needs thermal compounds to effectively dissipate thermal loads. Without them, our beloved gaming and content-producing machines would struggle to keep components cool during heated frag sessions, heavy workstation computations, or just simply browsing the web.
Not every system will need the most expensive compound, so even the most budget-minded system builders can rest easy knowing that even lower-cost pastes can still prove very effective. You can see our historical testing results with far more pastes after the test setup.
Test System Configuration and Testing Methods
|CPU||Intel i9-10850k LGA1200 (Comet Lake), all 10 cores: 4.6Ghz @ 1.190v|
|Motherboard||MSI Z490 MEG Godlike (BIOS ver. 7C70v12)|
|Memory||Corsair Dominator Platinum RGB, 16GB (2x8GB) DDR4-3600|
|Storage||Corsair MP600 M.2 2280 NVMe, 500GB|
|Graphics||Gigabyte GeForce GTX 1050Ti|
|Power Supply||be quiet! Dark Power Pro11 1200w|
|Chassis||Corsair Graphite 760T|
|Monitoring||CrystalFontz CFA-633-TMI-KU, 4x Dallas One Wire WR-DOW-Y17 sensors|
|Fan Control||Corsair Commander Pro, 100%/50% PWM Speed profiles (liquid cooling pump always @100%, if applicable)|
|OS||Windows 10 Pro 64bit|
For our thermal compound tests, we use the same hardware, CPU overclock, and configuration for each and every test to minimize environment variables in our testing.
We tested each thermal paste with a low-tension air cooler mount, high-tension air cooler mount, and a high-tension AIO liquid cooler mount. Each application was given a 1-hour burn-in using Prime95 with ten load and cooling cycles over the course of the hour; six minutes each with a ten-second cool-down between. Each testing load session was then executed for a one-hour load period, again using Prime95.
For the air cooling low- and high-tension tests, we used a large Noctua NH-D15 air cooler. We created the low tension mount environment by torquing the mounting screws to 1.13 Nm (10 in/lbs).
The low tension mounting tests help simulate cooler installs that might not use a backplate (like push-pin coolers) or those that do not allow high tension and compression across the CPU integrated heat spreader. Also, repeated tests are not consistently possible with push-pin mounted coolers: The pins can degrade after several mount cycles, which meant we needed to simulate these to maintain consistent test results.
Our high-tension air cooler mount involved tightening the mounting screws fully to the mounting plate and shows thermal paste performance with air coolers with backplates that allow for tighter mounting.
We used the EK-AIO Elite 360 D-RGB for the liquid cooling tests with all fans in a push+pull configuration. We performed these tests with the AIO pump block fully tensioned (tightened). We didn't test the AIO with a low-tension mount because liquid coolers almost always employ a backplate that allows a high-tension mount.
Overall, each compound was evaluated and stressed over a regimen cycle covering six hours with two different coolers and different mounting tensions, making for no less than 90 hours of compound testing for our initial round of tests.
Legacy Thermal Paste Testing - 85 Pastes Tested
Here's our legacy thermal paste testing chart that we generated back in 2017. As you'll notice, many of the same popular pastes in 2017 are still on the market, making it into our new round of 2021 testing.
We do have new testing equipment for our updated tests, such as a more modern CPU, motherboard, and coolers for our tests, but we adhered to the same test methodology employed in these prior tests. That means that you can use these legacy tests as a decent approximation of how the newer pastes compare to the older pastes, too.
We'll be adding more thermal pastes to our new hierarchy; stay tuned.
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