Get the latest insights
Subscribe to get money saving tips and product offerings for your next custom build.
By subscribing you agree to our terms
If you have ever built your own PC you will know all about thermal paste, the grey paste that can be a bit of a pain to apply, it seems to get everywhere.
Everywhere you turn on the internet you will see someone swearing by a particular brand or application method that is the be all and end all. As such thermal paste is a bit of an unknown quantity.
In this guide, I will explain some of the science behind different thermal pastes, the best pastes you can buy, and what is the best way to apply it.
Thermal paste is used to plug tiny gaps between a heatsink and any component that needs cooling. The manufacturing process of these parts means that it is nigh on impossible to have the contacts between a heatsink and a chip be completely flush with each other. This means that the heat dissipation potential is not as high as it could be, resulting in inefficient cooling.
Applying the thermal paste means that these gaps are filled in and the heat can more efficient be dissipated between the two components. If you don’t use thermal paste you risk your components dying prematurely.
There are three different types of thermal pastes Metal, Silicon, and Ceramic.
Metal thermal pastes are the best performing and most commonly used for consumers. Silicon is more widely used by manufacturers as it is cheaper than metal or ceramic, but it doesn’t perform quite as well. Ceramic is not quite as good as metal but the plus point is that it doesn’t conduct electricity so if you make a mess you don’t have to worry about shorts.
People have different opinions on this matter and a lot of people will stand by their own method that seemingly shaves that extra one or two degrees of their load temps.
There are a few different methods with colloquial names. A lot of people tend to just use a pea sized amount in the middle of the CPU. Others tend to draw a thin line down the middle of the CPU. There is also a circular method but it really isn’t that widely used.
In reality, there isn’t much of a difference between the methods, the big difference comes from making sure you use the right amount of thermal paste. The more thermal paste you use, the harder it is for heat to dissipate from the CPU to the heatsink. The key is to just use enough to cover the surface of the CPU and CPU block.
When you place the heatsink on the CPU, you have to make sure you do it as evenly as possible. This is to make sure that the thermal paste spreads equally across the surfaces creating a nice thin lock between the two components.
There is no hard and fast rule when it comes to replacing thermal paste, the best thing to do would be to keep an eye on your temperatures and when you start to see an increase replace your paste.
If you don’t want to monitor temps, you can replace every year or so, a lot of people tend to upgrade around that time period so take that as an opportunity to give your PC some maintenance.
Arctic Silver 5 is probably the most well-known and trusted thermal paste for PC enthusiasts. You will see many people swearing by this thermal paste, as such it is a sure-fire choice for your machine.
It comes in at just $5 for 3.5 grams of the stuff. That may not be as much as others in this list for the money but the quality you get is undeniable.
Arctic Silver 5 is a ceramic based thermal paste that comes in the standard syringe type tube. What sets the Arctic Silver 5 apart from its rivals is the fact that it uses a 99.9% silver compound, this is key because silver has one of the highest thermal conductivity capacity of any material.
Despite this silver composition, Arctic Silver 5 is still considered ceramic based but it is important to note that it is still a little capacitive compared to other ceramic pastes due to the silver, so make sure not to get it everywhere.
If you want a fantastic thermal paste without having to empty your wallet, you cannot go wrong with the Arctic Silver 5, just make sure to perfect your application technique as not to waste any of the 3.5g that you get.
If you want the absolute best thermal paste that money can buy then the Liquid Ultra from Coollaboratory is the choice for you.
It comes in at just under $14 a metal compound that is sure to shave quite a few degrees of off your CPU temperatures. There are just a few problems with the Liquid Ultra though that make it a bit difficult to recommend to anyone but the most ardent of coolers.
Firstly, Liquid Ultra cannot be used with aluminium heatsinks, this is due to the compound reacting with aluminium to insulate rather than conduct. Secondly, there is a very strict and set process for applying Liquid Ultra to your CPU and it requires a lot of fiddly handwork.
First you have to clean all surfaces with at least 70% proof isopropyl alcohol and a cleaning pad, this is to make sure there are no impurities. Then you must spread it evenly across the surface of the CPU using the included brush that isn’t the most intuitive of things you will ever use.
This is all whilst making sure that the thermal paste does not touch any of your other components because of the metal composition of the paste will cause it to short.
The price may be steep considering you can’t use it on aluminium heatsinks, and the application process elaborate and tedious but many people swear by this paste and the extra degrees it can shave off. If you are serious about cooling and are experienced with applying thermal paste, Coollaboratory’s Liquid Ultra is one of the best you can get.
The Arctic MX-4 is one of the most popular budget thermal pastes that you can get today. On Amazon, it is always number one when it comes to thermal pastes.
This is due to the great bang for your buck that you get with it. You get enough to last you a long while and it comes in a great syringe type applicator.
Unlike the others on this list, the MX-4 is carbon based, this leads to issues with peak-temperatures but for the money it can be forgiven.
If you are just looking for a cheap thermal paste that does the job, you cannot go wrong with the Arctic MX-4.
The issue with the High-Performance is that it is very runny, in fact almost all of the CoolerMaster thermal pastes are. Due to its metal composition, this can make application a bit tricky, so you have to be extra careful when applying it. It does come with a spatula that you can use to spread it but this isn’t really worth the trouble.
It does perform very well though, it is up there with the best ceramic pastes but it underperforms when compared to its metal cousins.
Whilst it isn’t the best metal paste you can buy, if you want something that does the job a bit better than ceramic pastes, the CoolerMaster High-Performance thermal paste is definitely worth a look.
Noctua are known for making some of the greatest cooling solutions for PCs on the market currently and their thermal paste is no different.
The NT-H1 is ceramic based and offers great cooling capacity. Whilst the paste is a little drier than others on this list, this doesn’t affect application that much, the usual syringe applicator makes it a doddle to apply.
For just $6 you get more than the Artic Silver 5 with equal or better performance, so for the money you cannot beat the Noctua NT-H1.
There you have it, the best thermal pastes that money can buy, there are so many different ones to choose from but this list should make it that bit easier to find the one that works for you.
There is a lot of science that goes into thermal paste so keep an eye on where the industry is heading, they may find something in future that blows everything currently available out of the water.