Modern CPUs produce plenty of heat, especially when you’re doing computationally intensive tasks. How well you manage that heat will ultimately impact the both the performance of your PC and the lifespan of your processor. Even if you’re only interested in casual use, like browsing the web, having an effective approach to heat management is still in your best interests. And if you’re using a powerful processor and expect to put it to task, heat management can be mission critical.
Thermal paste is a thermally conductive substance, usually sold in fluid form, which is applied between a CPU and its cooler. Its application ensures there’s no gap between the processor and its cooler, which helps to dissipate heat through their connection. But as you might suspect, not all thermal pastes are the same. You can most considerable differences in their lasting power, performance, difficulty of installation, and cost.
For example, the thermal paste that’s historically been included with Intel CPUs has been constructed to have an incredibly long lifespan. Although its ability to dissipate heat isn’t anywhere near as good as an aftermarket thermal paste, it’s good enough for keeping a modestly powerful CPU fairly cool for the better part of a decade. That longevity-based design allows the average PC user to live their lives without ever having to think about thermal paste, but it also ensures much higher temperatures than you’ll get with virtually any other type of paste.
Sometimes longevity should be your priority, and sometimes it shouldn’t. If you’re running particularly powerful hardware and expect to reach higher temperatures, then you don’t want the performance of your system’s expensive hardware to be bottlenecked by the wrong thermal paste. However, thermal pastes which are exceptionally effective at dissipating heat typically only last a few years before they lose efficacy and need to be reapplied.
Types of Thermal Paste
Choosing the correct thermal paste is about matching up with a paste that’s appropriate to the computer it’s being applied to, and to the skill level of the person doing the application. For the most part, you’ll want to avoid liquid-metal pastes. Metal-based pastes are incredibly effective at dissipating heat, but they’re also dangerous for inexperienced users to apply.
That’s because most liquid-metal pastes are made with electrically conductive metallic bits suspended in their solution. Even a drop spilled on the pins of your processor will instantly destroy it, and mostly likely void your warranty in the process. Spills on the motherboard have to be rigorously cleaned up, and still may end up causing damage.
Novices will want to stick to ceramic-based pastes, which tend to be gray or white. They’re made of a silicone paste combined with ceramic powder. Application isn’t as risky as metal-based pastes because they use compounds that don’t conduct electricity. Non-conductive ceramic alternatives are also a worthy choice.
Viscosity and Ease of Installation
The dangers of electrical conductivity aside, some pastes are physically easier to apply than others. Even if you’re an experienced builder, you’re going to want to know something about the viscosity of a paste before you try to apply it. Understanding the viscosity involved can help prevent you from squeezing out the wrong amount of paste.
Additionally, the kind of application techniques you use on a thick paste aren’t necessarily the same for those use for thinner pastes. Generally speaking, thicker pastes tend to be more difficult to apply. But as long as you’re paying attention to the viscosity of the paste you choose, you can prepare for installation by searching for an appropriate application method.
Quantity of Paste
If you’re only installing thermal paste on one or two processors, then you won’t have to worry about the availability of thermal paste. Virtually every thermal paste tube on the market will have enough paste to install a CPU. But if you’re doing more than one humble installation, then you’ll want to take notice of the quantity of paste you get with your purchase. Some manufacturers provide enough to cover a dozen different independent installations.
Thermal Paste Lifespan
When you’re considering the quantity of thermal paste included in a tube, it’s not a good idea to start developing illusions about getting years of use from the paste. The shelf life for many thermal pastes is only two or three years. Thermal paste doesn’t age well. After you’re certain that you’ve successfully installed your CPU cooler, you’ll probably want to throw away whatever paste is left over.
The application life of each paste varies as well. On the high end, you’ll find pastes which claim to maintain their efficacy for eight years. On the low end, you’ll find manufacturers who suggest replacing their paste every two or three years. The good news is that even after three years, those pastes will likely continue to provide adequate performance, albeit diminished from their original state.
If you’ve already spent hundreds on a processor, you shouldn’t undercut its performance by trying to save a couple of bucks on thermal paste. For anyone interested in overclocking, the paste you choose will have a drastic impact on the performance of your machine. Of course, that doesn’t mean that thermal paste has to become a serious investment. You can find plenty of extremely high quality pastes around or under $20.
Anyone familiar with PC cooling will know the name Arctic. And their MX-4 scarcely needs an introduction, as one of the most popular thermal pastes in the world. Artic has an exceptionally strong reputation for quality, and their thermal paste consistently benchmarks among the best thermal pastes in the world. It’s also one of the most competitively priced thermal pastes on the market, making it an excellent choice for almost anyone.
MX-4 doesn’t contain metallic particles, so if you make a spill on your board there’s no need for a panic. It could make direct contact with every pin on your CPU, and you’d only have to be worried about cleaning it up. Fortunately, even the risk of a spill is minor because of the soft consistency of the paste.
And the MX-4’s performance is built to last over time. According to Arctic, it doesn’t need to be reapplied for up for eight years. The MX-4 comes in a 0.64-ounce tube, providing enough thermal paste for multiple applications. But its relatively low shelf life means you probably won’t want to hold on to extra paste after you’re confident that you’ve successfully installed your cooler.
Difficulty of Installation
The MX-4’s paste has a smooth consistency that makes it easy to apply. Even if you’ve got no experience applying thermal paste, you should encounter relatively little risk of creating a mess or accidentally applying too much. The simple design of the application tube makes it especially easy to avoid problems voiding your hardware, or creating spills elsewhere.
Thermal Grizzly Conductonaut
If you’re looking for multiple applications from your paste, you’ll want to look carefully at the Thermal Grizzly Conductonaut. It comes in a spacious 1-gram syringe, which accommodates an accessible and steady application, and provides what could be called an amble amount of paste. Relative to similar thermal paste syringes, this container is particularly long and needle-like. That makes it easy for razor-sharp accuracy when applying your paste, which can be ideal for applying thermal paste within cramped spaces.
The Thermal Grizzly Conductonaut tube includes enough paste for roughly eight full applications. While this brand isn’t exactly a household name, their paste does hold up to scrutiny. It has an exceptionally high thermal conductivity, which is advertised as being 73 W/mk. But you don’t need to understand the units, all you need to know is this paste is made to put cooling first and foremost.
Difficulty of Installation
Relative to other silicon-based thermal pastes, this paste is marginally more difficult to apply. Using the syringe is simple enough, and it allows you to get a highly controlled a measured amount of the paste out. But the paste itself is quite firm, so you’ll need to find a small tool with which you can help spread it evenly. The most common installation methods, like the pea method, aren’t going to work well for applying this paste.
Anyone familiar with PC cooling will know the name Noctua. Their fans are widely regarded as some of the best on the market, and their thermal pastes live up to the same high standard. The NT-H1 is a mixture of particles that’s unique to Noctua, helping them achieve their own unique signature stability. And although the NT-H1 is inexpensive, it offers thermal performance that rivals the best liquid metal pastes in the world.
Noctua’s unique paste mixture isn’t electrically conductive. It’s also non-corroding, making it suitable for common copper and aluminum coolers. Within each tube of the NT-H1 there’s 1.4ml of paste, which is enough for more than a dozen full applications. Noctua’s recommended storage is two years, which essentially means you’ll want to throw out the tube when you’re done. The NT-H1 is expected to last for 3-years of use, provided you keep your system running under 90˚C.
Difficulty of Installation
Noctua’s paste applicator makes the NT-H1 easy to apply. It offers a generous spread so it’s easy to use the pea-method and get an easy application. The paste itself isn’t particularly slimy or hard, making it easy to apply. But that can backfire for people who are inexperienced because you could spray too much and end up with some on your motherboard.
Arctic Silver 5 AS5
Arctic describes the Silver 5 as a high-density paste, and it shows once you squeeze it from the tube. As the name suggests, the Arctic Silver 5 AS5 is composed of 99.9% pure micronized silver, and is non-electrically conductive. That design allows for highly effective and lasting cooling, albeit with a slightly more difficult installation.
This paste uses a micronized silver paste alongside ceramic particles to create a high performance and long-lasting design. The aluminum oxide, boron nitride, zinc oxide solution provides lower load temperatures than you’ll get from standard compounds. The 3.5-gram syringe will cover more than a dozen CPUs, or about half a dozen large CPUs, or two heat plates. All in all, you can squeeze out about 16 square inches of effective coverage from one simple tube.
Difficulty of Installation
Even if you’ve installed a number of thermal pastes before, if you’ve never seen Arctic Silver 5 paste, then you’re going to be in for a small surprise. That’s because it’s actually a synthetic-oil based compound which is completely free from silicone. And its oil-based design allows the Silver 5 AS5 to apply to processors in a way that other thermal pastes simply can’t. After it’s been applied and your CPU is turned on for the first time, the heat from your CPU will gradually thin out the paste, leaving behind only the most thermally necessary elements.
The paste then slightly thickens over the next few days until it’s achieved its desired consistency. The resulting application doesn’t just provide an excellent, evenly spread escape for thermal energy. It also provides a kind of lasting stability that can help keep this paste working for years to come. The high-density nature of this paste means installation is a little more hands-on, but ultimately should be manageable for anyone.
Choosing Between 4 Effective Thermal Paste Compounds
The Noctua NT-H1 performs nearly as well as top-shelf thermal paste compounds, but at a fraction of the price. If you’re looking to save money on thermal paste and not suffer any performance repercussions, then the NT-H1 is a great choice. You probably won’t have to replace the paste even after the three-year period suggested by Noctua. In the interests of keeping your performance in top-shape, you’ll probably want to replace the paste eventually. But with the inexpensive nature of the NT-H1, you won’t mind having to do it.
The Thermal Grizzly Conductonaut is a good alternative to Noctua’s NT-H1. It has similar thermal performance at a similar price, but comes with a longer shelf life. Although the NT-H1’s extremely high thermal conductivity will marginally outperform the Thermal Grizzly Conductonaut, the Conductonaut’s lasting power makes it a better choice for an inexpensive one-time application. If you’re looking for high thermal conductivity and you don’t see yourself refreshing your thermal paste after in the years after you’ve applied it, then this paste is a good choice.
The Arctic Silver 5 AS5 is a good choice for people who are looking to apply paste to multiple CPUs. It’s a great way to get bang for your buck, providing effective cooling for an enormous number of surfaces before the tube is exhausted. The oil-based paste is a little unusual, and its lack of silicone is somewhat reflected in the price. But it’s performance is marginally better than what you’ll find in less expensive thermal pastes. It’s a good choice for someone who doesn’t mind spending a little extra to get all the performance they can.
If lasting power is the most important consideration, then the Arctic MX-4 is your best bet. It’s safe and incredibly easy to install. It’s designed to last 8 years, which means your CPU will probably be outdated before your paste needs to be changed. The tube doesn’t provide enough paste for several applications, but it’s more than enough to complete two separate processors and still have a touch left over. For someone who wants an inexpensive and reliable solution, the MX-4 is a safe bet.