Best CPU Thermal Paste and How Often to Replace Apply? Find Out Now

CPU thermal paste is a critical component for computer/laptop cooling. Overheating can reduce performance and lifespan, and the system may force throttling to prevent overheating. In cooling systems such as air cooling and liquid cooling, thermal paste is a low-cost and highly effective option, making it one of the best choice for CPU cooling. However, if budget is not a constraint, upgrading to a liquid metal thermal paste or even a liquid cooling system could be considered.

What is thermal paste?

Silicone-based thermal pasteGoodCheapWidely used, good efficiency, non-conductive, safe to use, mainly uses metal oxides as the primary thermal conductor material.
Carbon-based thermal pasteAverageCheapSafest option (technically) as it contains no metal particles and is also non-conductive like silicone-based thermal paste.
Liquid metal thermal pasteExcellentExpensiveDifficult and risky to use, highly conductive. If not applied carefully, it may cause short-circuits and damage the components or motherboard. Often made of metal gallium and may form an alloy that becomes brittle upon contact with aluminum. For more details, click this link.
Phase-change materialsExtremely effectiveHighly expensivePrimarily used in industrial applications, phase-change materials are mixtures that undergo a phase change (usually solid/liquid transition) at around 70°C. They store and transfer heat through an endothermic reaction. These are not exactly thermal paste.


Ideal Type and Thermal Conductivity

For enthusiasts with high-end computers equipped with water cooling and experienced in applying thermal paste, using liquid metal thermal paste is fine. Otherwise, it is generally recommended to use a high thermal conductivity and long-lasting thermal paste that is slightly behind liquid metal thermal paste, such as silicone-based thermal paste. It provides significant cooling effects without the risk of damaging the motherboard or components even if accidentally spill it out.


What is Thermal Conductivity?

Thermal conductivity (thermal rate) refers to the ability of a material to transfer heat under stable conditions. In metals, higher electrical conductivity often corresponds to higher thermal conductivity. Therefore, thermal paste often includes metal components to enhance its thermal conductivity while using silicone gel as the base. It might seem that the more metal, the better the effect, but in reality, excessive metal can reduce the paste’s spreadability, making it less even or too thick. High-metal alloy thermal pastes also age faster, resulting in shorter lifespans and decreased cooling efficiency.


High Thermal Conductivity ≠ Better Effect

First and foremost, the actual cooling effect is determined by thermal resistance. Lower thermal resistance leads to better cooling. It comprises three factors: Thermal conductivity, Thermal paste thickness (thinner is better) and Contact resistance. Additionally, thermal paste serves as a filling material for the gaps between the component and the “component x heatsink” interface. While the component’s surface may seem smooth, at the nanometer/micrometer scale, it is actually rough and uneven, even with pits or scratches. Therefore, the thermal paste’s viscosity and evenness after application are crucial.


CPU Thermal Paste Recommendations and Testing

After all the explanations, the real focus lies in the testing results. The chart below shows the test results for 9 well-known brands. Using the same silicone-based thermal paste under the same test environment, the Koolingmonster Organic Silicon High-Performance Thermal Paste KOLD-01 performed the best. Aside from its thin application (only 0.02mm, while the market average is 0.5mm), the official website claims it can last 5 years, which is longer than the typical 3-year lifespan.
Note: The test environment includes an Intel i3-10105F CPU, ASUS H510M-E motherboard, Golden Field cooling system, and 8GB ADATA RAM. After applying the paste under the same conditions, the CPU temperature was measured for an average of 30 seconds within a 15-minute CPU stress test.

The highly-praised German Thermal Grizzly Kryonaut surprisingly lost to the KOLD-01. The following the middle-priced Gelid Solutions GC-Extreme and Noctua NT-H1. However, the cost for  a set of these pastes can buy many sets of KOLD-01. It’s such an affordable option. Maybe the price will increase in the future?



Unboxing and Impressions

Koolingmonster‘s thermal paste seems to be from a relatively new brand. I decided to try out the KOLD-01 to see how good it is. Aside from its excellent efficiency and long lifespan, it comes with  cleaning wipes, gloves, and a scraping tool. The step-by-step method will be explained in the next section. Additionally, the company provides extensive professional knowledge with  technical details, and testing data on their website, which is very informative!CPU散熱膏推薦與6種塗法解析;多久換一次最好?-3


Usage Instructions

If you’re using a high-quality thermal paste and still getting no results or even worse performance, it might be due to: too much/little paste, or not properly cleaning off the old thermal paste, or not applying pressure after spreading, or installing the heatsink incorrectly. Here are the step-by-step instructions and precautions for applying thermal paste. By following these steps, you can achieve the best cooling performance with your thermal paste. Under normal usage conditions, such as web browsing and watching movies, CPU temperature between 40-55°C is considered reasonable and normal, while under heavy loads such as gaming and intensive computations, temperatures between 65-80°C are also considered acceptable.


5 Steps to apply the paste

1. Remove the heatsink (fan or liquid cooling cold head).
2. Use the included silicon grease wipes from KOLD-01 to clean the heatsink and the old thermal paste on the CPU or GPU. The wipes are of good quality and won’t leave tiny cotton or residue. You can also use acetone or alcohol swabs to clean, but make sure to remove any fine cotton residue.
3. Clean it twice more with new wipes, ensuring all the remaining old thermal paste is thoroughly removed.
4. Let it sit for 2-3 minutes to allow the surface to dry.
5. Apply the thermal paste following the method explained in the next section. After attaching the heatsink, make sure to tighten the screws and wipe off any excess thermal paste.



Amount and Method

Typically, an application of about 0.2 ml (about the size of a pea) is sufficient. Through testing, it has been found that regardless of the application method used, 0.2 ml achieves the best cooling performance for a 3 cm x 3 cm-sized CPU. You can also use a thermal paste dosage calculator for estimation. The application methods are shown as below picture. Any of these methods can be used. However, for thermal pastes with poor flowability (often lower-quality ones), the Buttered Toast method is recommended. This involves using a scraping tool to spread the paste evenly. One important note is that the application amount should never be less than or equal to 0.1 ml under any circumstance.



How Often to Replace?

Most thermal pastes on the market contain a significant amount of volatile organic solvents, making them more prone to drying, cracking, and deteriorating. Therefore, they should be replaced after around 3 years to avoid affecting performance. If conditions are harsh (frequent high-load operations, improperly installed heatsinks, etc.), replacement every 1.5 years might be better. According to the data on the KOLD-01 official website, it can last 5 years due to its unique non-solvent formula, which reduces the risk of oil leakage and drying issues and does not contain any chemical volatiles, with a chemical volatility of 0.0% (market average: 1.1%) and no odor.


After improving CPU cooling, the next step is to upgrade to an SSD. According to my ASUS laptop’s test results, the boot time decreased from 4 minutes to 20 seconds after the upgrade. Check this link for SSD recommendations and the replacement process.

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