The thermal paste sits between your CPU's IHS and the cooler's heatsink to facilitate thermal conduction. It's also needed to fill the microscopic gaps between the two seemingly smooth surfaces to ensure maximum contact. While this might sound simple enough, the thermal paste gets more attention than it deserves. People often try to justify the necessity of expensive thermal paste, citing numerous advantages that it holds over the pre-applied paste on your CPU cooler. Aftermarket paste might be technically better than stock thermal paste, but the real-world differences are negligible, at least for most users. That said, those chasing every last ounce of performance from their high-end CPU can and should invest in high-quality thermal paste.

The stock thermal paste is fine for most users

Aftermarket paste doesn't make a meaningful difference

The pre-applied thermal paste on your cooler's heatsink gets a lot of flak from the PC community, but it's nowhere near as bad as people say. The quality of stock thermal paste might have been subpar a few years ago, but it has come a long way. Most gamers do not need to replace the pre-applied paste before mounting the cooler. It's perfectly capable of keeping your CPU's temperature within the comfortable range where you don't need to worry about performance loss. Cooler manufacturers often use their branded thermal paste, like Arctic's MX-6, Cooler Master's MasterGel, and Thermalright's TF7 for their coolers. These pastes offer 95% of the performance of other aftermarket thermal pastes, making them more than sufficient for the average gamer.

Even if you replace the stock paste with an aftermarket option, such as Thermal Grizzly Kyronaut, you'll not see more than 3–5℃ of a temperature drop. This difference isn't going to result in any performance benefits or extend your CPU's lifespan in any meaningful way. In fact, reseating your CPU cooler is more likely to impact CPU temps in cases where you're observing unusually high thermals. Aftermarket thermal paste doesn't equate to reduced fan noise either, since the temperature difference is negligible.

Aftermarket paste can offer more longevity and ease of application

It can be the right tool for the job

It's not like aftermarket thermal paste is completely worthless. It might not drop your CPU temperature by 10℃, but it has advantages in other areas. For instance, high-quality thermal paste can last longer, needing fewer replacements over the course of the PC's lifetime. This might not be worthwhile to the average user, since most people replace their CPU's thermal paste once or twice before replacing the chip or building a new system. That said, you might value the longevity if you intend to use a flagship CPU for around 10 years or more.

The other aspect to consider is ease of use. While thermal "paste" is slightly messier to apply and clean, thermal sheets offer a superior alternative in almost every way. They can also be non-conductive and are way simpler to apply to the CPU's IHS. They also last way longer than thermal paste, allowing users to minimize replacements. Some phase-change thermal pads can even change their physical state from solid to a liquid-like substance as the CPU temperature rises. They revert to their solid form once the CPU temperature drops. This allows much more efficient contact between the CPU's IHS and the cooler's heatsink.

Liquid metal is also a Thermal Interface Material (TIM), used for direct-die​ cooling in extreme overclocking. It's risky to handle and not recommended for anyone but a small niche of users, but it's the only option if you're chasing overclocking records. So, aftermarket TIMs are useful in edge cases, but overall, pre-applied thermal paste is just fine for most people.

Enthusiasts value the minor performance difference

The additional expense isn't a problem

The average user might struggle to find aftermarket TIM useful, but enthusiasts and benchmarking professionals might value every degree of temperature improvement. If you're chasing overclocking records by pushing your high-end chip to the extreme, you'll want to maximize your chances, which necessitates the best-performing thermal paste, sheet, or pad. Even if the difference is only a few degrees, it can mean everything to someone trying to keep their power-guzzling CPU as cool as possible. A few degrees can mean the difference between thermal throttling and the best performance a processor has ever recorded. A $15 thermal sheet or $25 phase-change thermal pad isn't a tough decision for enthusiasts eyeing the best results without delidding their CPU. It's simply another addition to the overkill hardware they're using, and it fits right in.

Pre-applied thermal paste isn't the bottleneck on your PC

Many users are quick to blame their thermal paste for their CPU's elevated temperatures. On the contrary, improper cooler installation, unoptimized BIOS settings, and stray background processes are much more likely to be the culprit. Before buying expensive aftermarket thermal paste, try to rule out the other possibilities. Stock thermal paste is perfectly capable of keeping your CPU's temps in check, and shouldn't be a cause for worry for the majority of users.