Choosing the best thermal paste for CPU may sound straightforward, but an overwhelming array of choices can turn this seemingly simple task into an agonizing experience. Finding and using the right product can make a world of difference to performance. It allows the processor to dissipate more of its waste heat to the cooler, ensuring the processor runs at ideal temperatures. Good thermal paste is equally significant if you're planning to overclock your rig to its maximum, including top-of-the-line CPUs, which can also hit fairly higher overclocks.
Every performance enthusiast has their go-to favorite paste brand, but the industry evolves rapidly, with new formulas cropping up from time to time. While this inevitably presents the burden of choice, it conversely means there are plenty of top-of-the-line products at the user's disposal. The challenge then becomes unraveling the proverbial haystack to find the needle. Fortunately, we've put together 5 of the best thermals pastes, including a few notable mentions, to give your CPU that desired massive push:
Best Thermal Paste for CPU in 2021
1. Noctua NT-H1 - Best Overall
- Renowned premium-grade thermal compound for optimal heat-transfer from the CPU...
- Easy to apply (no need to spread before heatsink installation) and easy to clean...
- Not electrically conductive and non-corroding thermal grease: no risk of...
- Trusted Noctua quality with excellent long-term stability: recommended storage...
Anyone who's been around the block long enough is familiar with the name Noctua, similarly well known for their top-drawer fans. The NT-H1 is a compound unique to Noctua, a mixture of particles fundamental to their own unique signature stability. The best part is, it's then well-priced while still rivaling some of the best liquid metal thermal paste options on the market.
The unique compound is not electrically conductive. That, plus non-corroding, make the NT-H1 ideal for popular copper and aluminum coolers. The tube contains 1.4ml of paste, enough to last you through more than a dozen full applications. However, the recommended storage duration is two years, or plausibly three, if you can keep your system consistently running under 90˚C.
It comes with a paste applicator that makes the application process easier. Furthermore, the compound itself is neither too slimy nor too hard. You'll get a generous spread off the cuff, especially if you're experienced.
2. Cooled Systems: Arctic MX-4 - Best for Air
- WELL PROVEN QUALITY: The design of our thermal paste packaging’s has changed...
- HIGH PERFORMANCE: With excellent temperature reduction performance, the MX-4 is...
- SAFE APPLICATION: The MX-4 is metal-free and non-electrical conductive, which...
- HIGH DURABILITY: In contrast to metal and silicon thermal compound, the MX-4...
The Arctic MX-4 requires no introduction. It's undoubtedly one of the most popular thermal pastes globally, further cementing Arctic's great reputation for quality.
It doesn't contain metallic particles, which should be a relief if you've ever spilled thermal paste on your board before. You could even simply clean it up if it made direct contact with all the pins on your CPU. Either way, such a risk is somewhat improbable, thanks to the MX-4's smooth consistency- which also makes the application process fairly easy.
According to the company, it has an application life of 8 years. In fact, it comes in a 4g/0.64oz tube, giving you enough paste for several applications. However, you'll still have to contend with a relatively short shelf life.
3. Cooled Systems: Thermal Grizzly Hydronaut - Best for Water
- Thermal paste ideal for optimizing thermal conductivity
- Thermal conductivity: 11.8 W / mk
- Thermal resistance: 0.0076 K / W
- Electrical conductivity: * 0 pS / m
The Hydronaut, as the name suggests, is designed for water-cooling systems. Nevertheless, it still performs quite well with any cooler.
The Thermal Grizzly Hydronaut has a couple of appealing numbers. Its thermal conductivity, as advertised, is an outstanding 11.8 W/mK. On various tests, it's also shown to consistently keep the temperature at a nice and cool 54°C (113°F), even when the processor is doing some intensive and heavy lifting.
This particular thermal paste is designed with beginners to overclocking in mind. If you're just getting started and have a water cooler CPU, you might want to consider this option.
4. Thermal Grizzly Kryonaut - Best for Overclocked Systems
- Thermal paste ideal for optimizing thermal conductivity
- Thermal conductivity: 12.5 W / mk
- Thermal resistance: 0.0032 K / W
- Electrical conductivity: * 0 pS / m
Yet another top product from Thermal Grizzly, the Kryonaut breaks away from the company's usual naming scheme. It's not engineered for sub-zero cooling solutions. The name simply indicates cool temperatures.
It has a remarkable 12.5 W/mK thermal conductivity rating, easily making it the top-rated CPU thermal paste featured on this guide. It's also non-electrically conductive, which is definitely a plus. Chances are, this product will just be as effective for GPUs.
5. Arctic Silver 5 - Best Budget Wireless
- 99.9% pure micronized silver
- Non-electrically conductive
- Will not separate, run, migrate or bleed
- Thermal conductance: >350 000W/m2 degreesC (0.001 inch layer)
For a couple of years now, the Arctic Silver 5 has been the best budget thermal paste on the market.
For starters, this is a high-density paste made of 99.9% pure micronized silver. It's also non-electrically conductive. The thermal conductivity rating is an impressive 8.9 W/mK. It's certainly one of the coolest-storing thermal pastes available. The Silver 5 has been tried and tested to maintain processors under 53°C (127°F), even on maximum performance.
The company even claims that this thermal paste never dries out. Somewhat true to their word, there are hardly any reported instances where users experienced heat-related component failure because their thermal paste went bad.
Other notable mentions that didn't make it on the list but would still get the job done remarkably well include:
- Thermal Grizzly Conductonaut
- Thermal Grizzly Aeronaut
- Cooler Master MasterGel Maker Nano High Performance
- Cooler Master New Edition
- Gelid GC-Extreme
How Do Thermal Pastes Work?
A thermal paste-also referred to as a thermal compound, thermal grease or Thermal Interface Material (TIM) - is basically a heat transfer agent on the CPU's Integrated Heat Spreader (IHS). A processor generally generates plenty of heat during operation. As you already know, high temperatures can cause fatal damage to components, such as the processor itself or the GPU.
There two main kinds of CPU coolers:
This is a component that sits under the CPU to facilitate heat transfer, the process that subsequently cools the IHS. Traditionally, air coolers are made of a metal base that comes into contact with the processor. Heat is then transferred through the metal block and channeled to copper pipes. These pipes lead to the trademark thin metal fins with a running fan which dissipates the heat further.
This works on a fairly similar principle. The heat sink, with water running through it, sits on top of the processor. The processor's high temps heat the water, which gets channeled to a radiator. The radiator consists of channels and metal fins with fans that blow at the water to cool it down before channeling it back to the heat sink.
So, what does a thermal paste have to do with all of these? See, typically, metal isn't perfectly flat, despite how it may look to the naked eye. This means there holes, divots and bumps that trap air when two metal pieces are pressed against each other. Air is quite the heat insulator, which impedes heat transfer from the processor to your heat sink. Thermal pastes are meant to plug these air gaps.
Since thermal pastes are liquid in form, they can be pressed down and into the tiny nooks and crannies that trap air between the metal. Furthermore, they are also engineered to be thermally conductive, further adding to the heat conduction capabilities. The question, therefore, is: What makes an excellent thermal paste?
Things to Consider in the Best Thermal Paste
1. Thermal Paste Properties
When you're looking at thermal pastes, you'll encounter a couple of properties that you're probably not particularly familiar with. Let's look at how they fit into the jigsaw.
This refers to the thickness or thinness of a thermal paste. High viscosity pastes tend to be thicker and normally adhere to the processor better. On the other hand, low viscosity thermal pastes are more "watery." This means they can potentially leak onto the motherboard, especially if too much is applied. Plus, they also tend to take a while to dry after they're set in.
b). Specific Gravity
This refers to the density or heaviness of the thermal paste and is expressed in g/cm³. If the density is too high, the paste might be too thick to even out uniformly. Too low, and the paste might end up too sparse to aggregate the metal to metal contact.
c). Thermal Conductivity
This is certainly the most essential aspect to consider in thermal compounds. It defines how good the paste is at moving heat from one part to another. It's measure in Watts per Square Meter of surface area (W/mK). Ideally, the higher the number, the more efficient the paste's heat transfer rate.
2. Thermal Design Power (TDP)
This indicated the amount of power a processor needs to use, more or less an estimate of how hot it can get. A higher TDP means it uses more power, hence generates more heat. Therefore, when you are looking through thermal compounds, it's important to keep in mind that a hotter processor requires an equally capable paste.
3. Ambient Temperature
The air around you also plays a substantial role in dictating the temperatures at which your system runs. If you happen to live in a conventionally hot region, you'll probably need a thermal paste that can match up to the ambient temperature.
This also extends to the air inside your system. If the components around your processor are running hot, this will raise the temperature of ambient air. This can impact your system and its performance, by extension, the same way external temperatures can.
4. Cooling Solution
Choosing the right cooling solution has a significant impact on how your system performs overall. As such, it's important, as a PC enthusiast, to set up a system with corresponding components. Otherwise, even the best thermal pastes can do no good if the rest of your system can't handle the amount of heat the processor generates.
5. Your Level of Familiarity
If you're a beginner, you might be worried about the risk of damaging your components. In which case, you'd rather opt for thermal pads first then thermal paste later down the line. They might not be as effective, but the risk factor is certainly minimized. Plus, they are fast and easy to set in.
If you're slightly more comfortable doing this on your own but still not as confident, then consider whether your paste options are electrically conductive. If you're a seasoned builder or overclocker, you may want to look into liquid metal thermal pastes.
Truth be told, you can only eke out so much shelf life from a thermal paste. Generally, they last for around 2-3 years. To put it more succinctly, they don't age particularly well. This means you'll have to throw whatever thermal paste is left after you've installed your CPU cooler.
Fortunately, each paste's application life is slightly longer, although it also varies from one product to another. Some pastes claim to remain efficient for up to eight years. The lower end of this would be around 3 years, when lower quality pastes might still work, albeit with diminished cooling performance.
Key Things to REMEMBER!
Here are a few critical precautions to always keep in mind when you're using thermal pastes:
- Never apply a thermal paste over another. Remove the old paste before you apply a new layer.
- Always use a spudger to get rid of solid or dried thermal paste.
- Never touch the paste, heat sink or chip directly since you might transfer particles to the paste, thus compromising its functionality.
Frequently Asked Questions about Thermal Pastes
1. What are the different types of thermal pastes?
Yes. Ceramic-based, metal-based, carbon-based thermal pastes and solid thermal pads are some of the options out there. Your final choice depends on the particular surfaces between which you want to close the gaps. Oftentimes, metal-based thermal pastes tend to be the past. Go for a compound that contains gold, silver or copper.
2. How do I apply a thermal paste?
There a couple of meticulous methods to do it. Here's one common way to do it:
- Clean the processor lightly without touching the golden parts.
- Remove any older thermal paste.
- Proceed to install the processor.
- Using a syringe, preferably, apply the thermal paste from the center to the sides. If you're using a pillow pack instead, follow the instructions on the packaging.
- Finally, install the CPU cooler or heat sink.
3. How much thermal paste should I apply?
A small blob, say pea-sized, in the center is more than sufficient at a go. In any case, the heat will spread the thermal paste anyway.