When building your own PC, it’s easy to overlook temperature control and the options available for cooling your PC. The focus is usually on the high profile components like the CPU and the graphics card. That’s understandable, since these are the big ticket PC components that have the largest impact on system performance. However, as these (and other components) work hard, they generate heat. And when your PC overheats, it slows down; the CPU and GPU will process more slowly to generate less heat and prevent damage.

This article is part of an educational series about PC components. Click here to see the rest of the series.

Having your PC slow down is not good, especially if you are in the middle of a game or exporting a file. If this happens constantly, the heat can cause physical damage. Components can suffer reliability issues after constant overheating. Pay attention to PC cooling during the design and build of your computer, and heat-based performance throttling won’t be an issue.

Here’s what you need to know about PC cooling.

Table of Contents:

      1. What gives off heat?
      2. How your system protects itself
      3. Overheating = damage
      4. How do I know my PC is overheating?
      5. How to keep your PC cool 

What gives off heat?

The two big culprits for heat generation in a desktop PC are the CPU and the graphics card.

PC Cooling
This Nvidia RTX 3030 graphics card features integrated cooling.

Graphics cards come with their own built-in cooling solution, and it’s usually very effective.

CPUs are equipped with a heat sink and usually come with a basic fan (check the box or product page to make certain). However, the included fan is going to be pushed to the limit if the CPU is constantly seeing high load demand. Overclocking the CPU—a common practice with gaming PCs—means that CPU is going to pump out even more heat. Another component that can contribute significantly to the temperature inside your PC’s case is high performance RAM. All other components from the power supply to storage are going to contribute some heat, but the CPU and GPU are the primary sources.

PC Cooling
Stock CPU fan typically included with CPUs is often inadequate for intensive use.

The focus here is on CPU cooling. That’s the weak link component that pumps out massive amounts of heat. The fan included in the box is meant for general duty use. If the CPU is going to be pushed, you’re going to want to upgrade to a CPU cooler. 

Don’t forget ambient temperature. If you’re using that PC in a warm room, the interior of the case and all the components are also going to be warm before you even turn it on.

How your system protects itself


Your computer’s CPU is equipped with a thermal management feature that will automatically start throttling performance when temperatures exceed a design ceiling. Unfortunately, that means your PC will immediately start to slow. 

Overheating = damage

Over time, overheating can cause physical damage to the CPU and to other components. A constant cycle of overheating and cooling causes everything inside the PC case to expand and shrink. Eventually, this can cause mechanical breakage in components. 

The bottom line is whether a performance hit or physical damage, heat is the enemy of your computer. Take care of it at the design and build stage, or if your existing desktop PC is overheating, upgrade its cooling system.

How do I know my PC is overheating?

It’s pretty easy to tell that your computer is overheating. If the fans are constantly blowing at high speed and causing excessive noise, that’s a good indicator. You’ll experience performance throttling, so the system will continually slow down. In extreme cases of overheating, the computer will shut itself down.

If you need assistance in determining whether your computer is overheating, GeekSquad can run diagnostics for you.

How to keep your PC cool 

Air cooling

PC Cooling
A CPU air cooler from Cooler Master, with black aluminum fins.

Air cooling is the simplest method for cooling a CPU. It starts with a conductive baseplate that is attached to the CPU’s head spreader. Thermal paste is used to ensure complete contact. Heat then moves to a heatsink with thin metal fins (ideally copper, but they may be aluminum) that allows the heat to dissipate more effectively. An active air cooling solution will also integrate a fan to increase airflow over the heatsink, moving the hot air away.

Liquid cooling

Liquid cooling solutions also use a conductive baseplate (in this case, part of the water block) that attaches to the CPU. Thermal paste is also used to maximize conductivity. However, that baseplate is part of a closed loop filled with liquid (usually distilled water). As it moves through the waterblock attached to the CPU, it is heated. The liquid then passes through tubes to a radiator, where it is exposed to air and cools. A fan attached to the radiator dissipates that hot air. A pump keeps the liquid circulating through the system.

PC Cooling
This liquid CPU cooler from Corsair includes a closed liquid circulation system and multiple fans to dissipate heat.

Liquid cooling is quieter and more effective—it’s very similar to the radiator used to cool a car’s engine.

All-in-one liquid cooling solutions are the most popular. They comprise of two hoses that circulate the liquid between the water block on the CPU and the radiator, making them easy to install. A custom loop solution is an option, though. Although more complex, this offers the option of expanding the system with additional loops to incorporate the GPU and other components as part of the liquid cooling system.

Don’t forget airflow 

So far we’ve dealt with cooling the CPU. But what about other components? The RAM and everything else. They all contribute to the interior of your PC case getting hot.

There are two issues to keep in mind here. One is space. If you have a smaller form factor PC case, there is less physical room between components for air to flow. That’s one of the reasons why those building a high-performance gaming PC often choose a full-sized ATX PC case. There are more slots available and more space to work in, but there is also more space for airflow.

PC Cooling
A computer case ventilation fan from Corsair.

Adding case cooling fans will help to keep air moving, cooling all the PC components. The usual configuration is to have an intake fan at the front of the PC (drawing fresh air in), and a second fan that exhausts the hot air out the back of the case. You don’t want to have only exhaust fans or you end up with unbalanced air pressure inside the PC case, which causes issues like excessive dust buildup. Speaking of dust, it helps if any intake fans are equipped with filters.

When considering fans, there are two main measurements that come into play. First is airflow. This is measured in CFM; larger numbers are better. The second is noise, measured in dB. In this case, lower is better. So you want a fan with high airflow and low noise—which generally means that larger fans are better.

PC Cooling
Thermal paste tube from Corsair.

Thermal paste

Thermal paste is a compound that improves the heat transfer between a CPU and an air or liquid cooling system. It’s a necessary part of the CPU cooler installation, and that means any PC cooler kit likely includes it—either pre-applied, or in the box to apply yourself.

However, if you decide you need more, it is also sold in tubes. Thermal paste is not used with case fans.

RGB lighting

We can’t talk about any PC components these days without talking about RGB lighting. PC gamers are especially fond of these programable LED lights, and since fans are components that are visible, there are naturally options that include RGB lighting. Some liquid coolers also incorporate RGB lighting on the waterblock. If you want to light up a PC gaming rig, you have plenty of options for doing so as part of the PC cooling installation.

You’ll find all your PC cooling needs at Best Buy

Best Buy carries a wide range of PC cooling solutions. Whether you’re building your own PC or upgrading an existing computer, you’ll find air cooling, liquid cooling, case fans, thermal paste, RGB lighting options, and everything you need to keep your PC cool.

Of course you’ll also find all the other PC components you need to build or upgrade a computer. To learn more about all the different components that go into building a PC, be sure to read the rest of the posts in this series.

Brad Moon
Editor Computing solutions
I’m a long-time electronics and gadget geek who’s been fortunate enough to enjoy a career that lets me indulge this interest. After 13 years as a product manager with a leading Canadian tech company, I transitioned into a full-time career of writing about technology. I’ve contributed to a range of publications and websites including Forbes, Wired, Gizmodo, Lifehacker, About.com, MSN Money, the Winnipeg Free Press, InvestorPlace Media, Shaw Media and—combining technology and my three kids—I’ve been a Core Contributor to the award winning GeekDad blog since its launch in 2007.

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