How Heat Affects Your Computer, And Should You Be Worried?

From time to time, we all get concerned about our computer’s temperature. But should we be worried? How exactly is your PC affected by heat? And what does it do to cool itself down?

Whenever you hear that little fan overdoing itself, mild panic might set in. Heat does affect your computer – but is it as bad as it sounds?

Which Components Generate Heat?

Thermal radiation is just the by-product of electromagnetic movement within millions of circuits, and the internal resistance it encounters – or to put it another way, electricity powering your computer is the simple reason why your computer becomes hot. Even LEDs produce it, though it’s minimal because the amount of electricity needed to function is low. Naturally, the volume of electricity needed for each component varies depending on the operations being performed, but there are some consistently with higher temperature output.

A computer’s core, its Central Processing Unit (CPU), naturally generates heat as it carries out algorithms, as does the Graphics Processing Unit (GPU), which typically handles 3D imaging for display. Gaming can result in higher temperatures, especially as they often require GPUs to carry out complicated calculations (in many instances, the GPU can generate more heat than the CPU). Hard disk drives can also contribute to heat generation, especially when copying large files.

Similarly, the optical disc drive can generate large amount of heat when playing DVDs or CDs, both as it forces discs to spin and as it reads the contents using a laser.

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It’s important to remember that room temperature, too, affects the internal workings of your computer. Higher room temperatures can affect performance, especially exceeding 80°F/27°C since the computer’s internal heat will be greater.

How Does Heat Affect Performance?


As part of the PC’s own cooling system, the motherboard, comprising of major components like the CPU and memory banks, instructs intensive applications to slow down. To avoid damage, it can even instruct components to shut down as a fail-safe. In some cases, this can cause your whole computer to turn off without warning; in extreme circumstances, this can occur continually until a new fan is fitted. This can particularly be a result of overclocking, running the CPU at a greater speed than intended by its manufacturer.

For many of us, we just accept that the more we use a PC, the more it slows down. Sometimes, minor calculations are wrong, but the computer soon corrects itself. Heat can also cause your computer to freeze, resulting in you restarting. More often than not, however, performance is not greatly affected; in fact, mostly, you won’t even notice.

But that doesn’t mean overheating doesn’t have greater consequences.

How Does Heat Affect Your Hard Drive?

Even though HDDs don’t consume nearly as much electricity as either the CPU or GPU, they are very sensitive to temperature changes, and excessive heat can irreparably damage your hard drive.

Handheld fan

A simple fact of physics: cold makes things contract; heat makes things expand. Through heat transfer, thermal expansion can warp the internals, meaning discs might not be read properly. This is an extreme example, but the HDD would need replacing.

More seriously, though, most agree that heat can reduce your hard drive’s lifespan, with National Instruments reporting that an increase of just 5°C above room ambient temperature can take up to two years off a drive’s expectancy.

Correlation between disc drive failure rates and high temperatures is questionable, however, even leading Google engineers to conclude that “at moderate temperature ranges it is likely that there are other effects which affect failure rates much more strongly than temperatures do.” Effects are greater with older drives, especially those over three years old.

Normally, data can be recovered, but when it comes to a damaged hard drive, things get a little more complicated.

How Does Your Computer Deal With High Temperatures?

The most notable way your computer draws heat away from sensitive components is with a heat sink — normally located by the CPU or sometimes GPU — which pulls heat from its surroundings through conduction and using fins to dissipate higher temperatures across a wide area, i.e. the rest of your computer’s case and out through vents at the back. Heat sinks vary in size depending on the system’s expected performance, based upon Thermal Design Power (TDP).

fanless motherboard

Heat sinks are most commonly made from aluminium alloys, a soft metal with high heat conductivity; copper is also extensively utilised, but it is more expensive than aluminium and greater in density so is only used in costlier and vaster industrial systems. Heat sinks are also used in some gaming consoles like the Xbox 360, which has to deal with very detailed graphics; a more highly-conductive material than aluminium is needed, so copper is largely used.

The majority of PCs also include an additional circular fan near the heat sink to aid airflow and reduce the effect on nearby components.

Larger fans are used to suck cooler air from the computer’s surroundings, convey it through the case, and expel it at the rear. On a hot summer’s day, you might open windows at the front of your house and leave the back door ajar, leading to fantastic air flow throughout; case fans in coordination with vents work on the same principle.

Designers also have to take into consideration the computer’s casing, so that suitably permeable materials help to dissipate excessive heat, as well as the space left inside between components.


More often than not, your computer will deal with heat exchange unnoticed. Occasionally, fans need to rotate quicker when performing complicated tasks like maintenance, copying files, streaming data, and sharing files – there are several ways to silence noisy fans if this becomes infuriatingly frequent, although this could indicate an underlying problem.

Yes, heat can affect your computer – both its lifespan and performance – but in most cases, you have little to worry about.

Image credits: Shutterstock

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