What is a Heatsink? Does My Computer Need One?

How well do you know your computer hardware? It’s a sure bet that you’ve heard of hard drives, processors, and RAM before, as they’re the main selling points for computers. If you dig further into computer hardware, you’ll also learn about graphics cards and their role. But what about heatsinks – do you know what they are?

In truth, heatsinks don’t come up a lot during hardware discussions. It’s not really something you’d buy a PC around, either! There’s a good chance that people who are new to PCs or haven’t explored the inside of their own, probably don’t know what a heatsink is exactly. So, what is a heatsink, and what does it do for your computer?

What is a Heatsink?

The role of the heatsink can be found in its own name; it’s a device that’s designed to extract heat away from vital components in your computer. While running, your computer’s hardware gets very hot, and the objective of the heatsink is to take the heat away and dissipate it before the components overheat. They’re most often found on processors and graphics cards, which are some of the bigger heat producers in your PC. Given how these components are very expensive in the higher ranges, keeping them cool is top priority!

Heatsinks come in an array of methods for dissipating heat.


Passive Heatsinks

Passive heatsinks look kind of like a radiator. Their conductive material means they can easily take the heat away from the components that need cooling down. These kinds of heatsinks are very reliable as they cannot technically break down. Also, due to the lack of fan, they provide a silent cooling solution for hardware. Unfortunately, due to the lack of fan, it has to cover a large surface area to help remove the heat. Passive heatsinks need decent room and a good air flow to ensure that they works optimally.


Active Heatsinks

Active heatsinks are far more commonplace in computers. They not only take the heat away but also dissipate it themselves, allowing them to work pretty much independently. The most common kind of active heatsink uses a fan to get rid of the heat. In an ideal situation, these fans blow the heat into an air flow, which then carries the heat out of the machine. They’re very effective just by themselves, but if the fan malfunctions or becomes clogged with dust, its efficiency drops by quite a lot.

Computing experts, particularly those who use their components to the extreme, will sometimes opt for liquid cooling. This is when components are cooled using a flow of contained coolant which takes the heat away from the processor. The coolant then carries and deposits this heat to a radiator which is cooled by a fan. They’re powerful at removing heat but also quite expensive and tricky to set up. Don’t worry about using one if you’re just starting out with computers.

Do Computers Need One?

Now that we know what a heatsink does, the question stands: does a computer need one? Are these essential hardware for a computer, or are they simply accessories for people who find their processors are running hot?

The short answer is: yes, definitely! Computers always need a properly-working and seated heatsink to work efficiently.

The long answer is this: The processors we have in our computers and laptops today are powerful and generate a lot of heat as a result. If you removed the heatsink from a computer and booted it, you’ll probably see it work from few seconds to a minute before the computer shuts itself off. This is because the processor has reached critical heat levels and caused a sudden computer shutdown. If you’re “lucky”, it’ll be because the processor has a built-in safety catch to prevent itself from burning out. If you’re not, the processor is now fried and unusable!

This is why when a user discovers their processor or graphics card is getting very hot, a common troubleshooting solution is to check the fans on it. If the heatsink is not functioning optimally, the processors will begin to overheat which will cause freezes, BSODs and sudden shutdowns and restarts. Some issues people will find with their heatsink is that it’s not “seated” properly (that is, they’re not tightly placed against the processor), that it’s clogged with dust, that its thermal paste is getting old, or the fan itself is simply giving up.

What About “Thermal Paste”?


You may have noticed a new terminology at the end of the last paragraph: “Thermal paste.” Given how they’re crucial for helping a heatsink do its job, let’s explore what thermal paste is. When attaching a heatsink to a processor, the contact surfaces of both won’t be perfectly flat, which will allow air to get between the two. Air is a bad heat conductor, so it will hinder the heatsink’s ability to extract heat, almost acting like a blanket on top of the processor.

By using thermal paste, you clog up the little gaps so that the seal between the heatsink and the processor is perfect. Thermal paste is specifically designed to conduct heat very well, so it acts at a much better heat transfer rate than air. This is why, when the paste gets old and less efficient, components begin to heat up a little. Always make sure there’s thermal paste applied when installing a heatsink – it’s essential for it to run at its maximum efficiency!

How Do Phones Stay Cool?

Throughout this article we’ve been discussing how heatsinks are essential for processors to prevent them from overheating. Despite this, when was the last time you remember a phone or a tablet needing an internal fan to keep cool? While some phones and tablets may have some way of dissipating heat, it’s nothing like the sort of hardware we see in a PC or laptop. How come mobile devices don’t really need heatsinks, while computers and laptops must have one?

The answer is quite simple: Phones and tablets use different processors than PCs. It’s easy to look at a phone’s quad-core processor and assume it’s the same as a quad-core desktop processor. While the core numbers may be the same, don’t be fooled – the architecture is completely different! Mobile processors have been specifically designed with two features in mind:

  • to run as cool as possible
  • to drain the battery as little as possible

After all, you don’t want a processor that drains the battery after minutes of use!

So how come we don’t use these efficient processors in computers and laptops, too? Well, having a processor work with less heat and power doesn’t come for free. In order to do this, we have to sacrifice the power these processors can work at. This means mobile processors are much weaker than their bigger counterparts and aren’t suited for more CPU-intensive tasks we can otherwise perform on PCs without issue.

Sinking Feeling

The heatsink is one of the least-discussed pieces of hardware in a computer. Despite this, it’s a vital component to keep a PC stable and healthy. Hopefully you’re now better versed in what heatsinks are, why they’re vital, and how they’re used in a computer.

Have you built your own PC before? If so, how much attention do you give the heatsink? Do you go for top quality and price, or do the cheaper models work fine for you? Let us know below.

Simon Batt
Simon Batt

Simon Batt is a Computer Science graduate with a passion for cybersecurity.

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