CPU Overheating: How to Easily Fix and Prevent It

Your CPU is way too hot! Programs are locking up; your games are stuttering and freezing. You’ve even experienced the dreaded blue screen of death. Your CPU has overheated itself into a state of shock!

Could it be that your PC is knocking on death’s door?

Fear not for there are answers to all of your overheating problems. You’ll learn how to cool your CPU down and keep it down. High temps are a common problem, that can be easy to diagnose and fix. For example, a CPU temperature monitor tells you exactly when your CPU breaks a sweat!

Before you can fix anything, you must first locate the problems. Also, stop slamming your mouse down out of anger. It did nothing to you!

The Most Common Causes of CPU Overheating

cpu with overheating thermometer on it

The title of this section should be “All of the Causes of CPU Overheating.” In reality, this covers 99.999% of temperature related issues. Anyway, we used the word “Most.” Here we go!

1. Dust Is Gross: How It Absolutely Causes Overheating

The primary cause of rising CPU temps is all around us—dust. PC cases are designed to lessen outside particles from entering. Many modern PC cases even come with removable filters, that trap dust as it floats in. If your PC lives long enough, small particles will get in. CPU overheating occurs, as heat can’t escape thru dust build-up.

Another problem of dust clogging your system is that it restricts airflow. Good airflow helps lower core temps, by reducing the ambient temperature inside of the case.

Ideally, you want to prevent dust from being an issue. You can do this by cleaning the entire inside of your PC case. Compressed air is often used to clean dust out of a PC. Do not blow using your breath, as saliva and moisture can damage components. Also, use a damp lint-free cloth to wipe down your computer.

Last, a shop vac works wonders if you need to suck dust out. Make sure you don’t directly touch any of your components with the vacuum hose. That’s due to the possible build up of static electric energy when it’s switched on. We don’t need to tell you why you shouldn’t shock your motherboard right? We are moving on then.

Compressed Air Cleaning Dust Out of Computer

No matter which method of cleaning you choose, always unplug your PC first. Also, make sure there is no moisture in or around your case before you plug it back in.

It is best to take apart your CPU and heatsink when cleaning. Removing your heatsink from your CPU allows you to clean dust from the cooling fins, vents, and fans. Second, it provides an opportunity to replace your old thermal paste, which is a small contributor to CPU overheating.

2. Old Thermal Paste: Is It Still Efficient? Was It Ever? How To Be Sure.

CPU thermal paste has a long shelf life as it’s made up of a mixture of silicone and metals—silver and zinc oxide. Anyway, it doesn’t hurt to replace old thermal paste.

Replacing thermal paste is easy. Dampen a lint-free cloth or coffee filter with rubbing alcohol and wipe it clean from both the CPU and heatsink. Then squeeze a pea-size dot onto the surface of the CPU and reattach the heatsink.

So, What’s The Theory On Thermal Paste?

Thermal paste works by filling in tiny gaps between the CPU and heatsink, that you can’t see with the naked eye. In the right amount, it improves contact between two metal surfaces. Apply too little, and it will cause CPU overheating from reduced heat exchange. If you apply too much, it can insulate and trap heat.

How Does Thermal Paste Work?
Why Do We Need Thermal Paste?

If it’s been three to five years since you’ve attached your heatsink, the CPU can slightly overheat. Also, if you used stock compound, it is not thermal paste, but low-grade thermal tape.

That said, thermal paste does still work, even when dried out. The reduction in temps can be as tiny as one or as much as three degrees. However, when your CPU is overheating every degree counts. Finally, thermal paste is only $5.00 a tube. It is very easy to wipe the old stuff off and apply a drop of fresh paste.

When fixing CPU temperature issues, leave no stone unturned. What if your paste was poorly applied to begin with? You will never know if you don’t check it!

Need more info on how to apply thermal paste? Find out more in this guide.

Now that your PC is clean on the inside make sure your heatsink is working to keep your CPU temperature down.

3. The Heatsink: Is CPU Overheating a Victim of Poor Contact?

You’ve removed dust from your pc and reapplied thermal paste. You had to remove your heatsink to do both of those correctly. Did you know that another reason for CPU overheating, could be the heatsink itself?

You may have just fixed another problem without even realizing it. What if your CPU is overheating because the heatsink isn’t properly seated? Take this moment in time to make sure you correctly attach it now, and your CPU temp issues could be history!

What is the best rule of thumb when attaching your heatsink? Tighten screws in an even, criss-cross pattern. This method allows the heatsink to sit flush against the CPU and evenly spread heat. In this case, CPU overheating occurs when heat gets concentrated to one side.

4. The Heatsink: Is All or Part Of It Not Working?

You need to explore the possibility that your heatsink could be useless. Though it’s not what you want to hear, it may need replacing. A heatsink can’t go bad in the general sense, but parts that attach to it can and do wear out over time.

How you learn of a faulty heatsink, is thru process of elimination. Knowing how a heatsink works to prevent CPU overheating will be useful in finding the problem.

On an air cooler, the heatsink siphons heat away from the CPU by sending it up thru conductive heat pipes to a large surface area—metal fins. Once heat collects in the fins, the fan blows air across the surface, removing heat and keeping your CPU temps down.

A liquid cooler uses liquid to carry heat away from the CPU to a large surface area called the radiator. The fans on the radiator blow air across the surface to dissipate heat build-up and prevent CPU overheating.

A great example of this is a cup of hot coffee. You blow across the surface to cool it down, which makes it drinkable. Your cup of coffee is acting as the hot CPU, and you—the heatsink.

How To Diagnose Your Heatsink Like A Pro

You removed one hurdle earlier when you cleaned the fins and fans of dust. By clearing the surface area of the heatsink, you’ve improved airflow. Next, check that the fan is coming on when powered up. If the fan comes on, check it’s RPMs under different loads. Do this with a fan speed controller or with temperature monitoring software, such as HWMONITOR

If the fan is working as it should, then check that heat is getting to the metal fins or radiator. In a liquid cooler, the water pump that moves heat to the CPU may not be sending heat away from the CPU. An air cooler is less likely to have the same issues that a liquid cooler has. That because for heat pipes lose contact, they need to break physically.

If you can’t know for sure, then bolt up the stock heatsink that came with your CPU. See if a different heatsink lowers your CPU temp. If the spare heatsink cools things down, but yours is not; it’s best to replace it.

If you’re strapped for cash, some cheap heatsinks do a great job at cooling things down. That is if you’re going to fix the problem of your CPU overheating.

If all is working as it should, then your problem could be up in the air—literaly.

5. Poor Air Flow Is Turning Up The Heat. How To Improve It.

Your heatsink controls CPU temperature, by taking heat created by your CPU and moving it to cooler areas. These areas are either the fins on your air cooler or the radiator on your liquid cooler. Take note; these aren’t the last stop during the heat exchange; surrounding air is.

Remember, the role of the fan on a heatsink is to blow away heat. By doing this, it keeps heat flowing away from the CPU. We don’t notice that the air around the heatsink plays a role in cooling, only because we can’t see it.

What happens when air becomes the same temperature or slightly warmer than the surface on the heatsink? If you guessed that your CPU would overheat you were correct! That seems to be the general theme of the article!

If air around your heatsink warms up, then the heat has nowhere to go. And so it goes nowhere, which is a problem for your CPU since it is the heat source. If the ambient temps inside of your case get too hot, it poses not only a CPU temperature problem but an issue for your entire system.

When heat inside of your PC case rises, your motherboard and graphics card can also overheat. The atmosphere in your PC case should safely hover between 45-50 degrees Celsius. The max air temp under a heavy load should never exceed 60 degrees C.

Preventing overheating by improving airflow is a simple fix.

How To Improve Internal Air Circulation

Many factors affect how air passes around and thru your PC. You removed one earlier, by clearing dust build-up inside of your case. Dust is the leading source of reduced air flow causing CPU overheating but isn’t the only reaso air doesn’t flow.

How does your wiring look inside of your PC case? Can you easily follow each cable or is it a tangled mess?

If your cables are all over the place, they could be blocking airflow that would otherwise be brought across the CPU to wick away heat. The air inside your case, like air outside, should be able to move freely.

Fresh outside air flows into the front of the PC. Here, it absorbs some of the heat put off by hardware and gets expelled out back as exhaust.

If your wiring is in order, then you should next check your fans. One thing to keep in mind is that warm air rises and cool air falls. You either want air drawn in from the front or under the case, and expelled thru the top or back of the case. Where you can pull air in and blow it out, all depends on your case layout.

How To Improve External Air Circulation

The last thing to explore when talking about case fans is that they are blowing in the right direction. You can figure this out by finding the sticker on the fan. If you’re looking at the fan sticker, you should be getting air blown in your direction.

case fan air flow direction
Air Is Blowing Toward You.

Remember, front fans suck cool air in and back fans blow hot air out.

Finally, is your PC in a well-vented area? Your case needs to breathe and has difficulty cooling off if it keeps sucking in hot air. Make sure your case does not have any obstructions around it, such as curtains, blankets or carpet. Also, make sure that it is not inside any enclosures around your desk, as heat can get trapped there too

There is one last thing for you to check at this point and it is a self-inflicted cause for your CPU overheating.

6. Overclock Fail: Is The Boost in Speed Causing a Boost In Temps?

You tried your hand at overclocking because you wanted your CPU to be just a tad bit faster. However, the result was a laggy space heater. If that’s the case, the way to a cold CPU is to undo your overclock. If you’re too proud to do that, then install a custom liquid cooler. Hint: The first option is easy and much cheaper.

So, how does a hot CPU cause poor performance? Leaving what is thought to be a safe temp range, it goes into self-protection mode in the form of throttling. That is, to cool itself down, it dials back on its performance. Throttling causes freezing, skipping and the infamous blue screen of death (BSOD).

CPU Throttling is a fail-safe that keeps you from having to buy a new CPU if core temps approach critical levels.

Get The Best Overclocking Software For The Job

Don’t know how to tune down an overclock? There’s software that allows you to tune your CPU, without having to go into BIOS. That’s good news for newbies, who don’t have a clue how to navigate BIOS. The most popular software for adjusting the speed of your CPU depends on what brand of processor in your PC.

If your overclock is already the result of a program on your PC, the easy fix is to look for a “default” button and select it. The second obvious solution is to delete the software, which may set your CPU clock speeds and voltage back to stock.

For an Intel CPU, you should use Intel XTU to adjust your overclock. However, if you’re using an AMD CPU—AMD OverDrive.

To keep your CPU from overheating it’s essential to learn how these programs function. If for any reason, to ensure that you don’t bake your CPU if you attempt to overclock again in the future.

How To Use Intel XTU To Tune Down Your CPU

Intel XTU stands for Extreme Tuning Utility and allows you to perform fine tuning on your Intel CPU. This fine tuning comes in the form of options, which allow you to not only overclock but stress test and benchmark your CPU as well.

The software also contains details about your main PC hardware. For example, under System Information, you will get manufacturer specs about your CPU, GPU, MOBO, Memory, OS, and BIOS version. There is manual tuning with options for more experienced users, who arent already having problems controlling their CPU core temps. The only option you want to select, for now, is “Default.”

Intel XTU is a good all in one tool that offers options for more than just overclocking. This software allows you to monitor your CPU voltage, temps, active cores, frequency, and even if and when the CPU begins throttling—and the total reduction in performance.

How To Use AMD OverDrive to Tune Down Your CPU

AMD OverDrive is easy to use software designed with beginners in mind. That’s not to say it doesn’t have options for enthusiasts—it has plenty. We are trying to fix an overclock that may have gone wrong, so in this case, we are beginners.

With the AMD OverDrive interface, as with Intel XTU, you can view your system info for different components such as your CPU, GPU, and RAM. As with all good overclocking software, there is an advanced mode which allows precise tuning of your CPU clock frequency and voltage. Remember, leave the “novice” tab selected for now.

To return your CPU to its stock settings, you first need to select “preferences” and then select “settings.” Under “profile” you will select “default.” That’s it! Everything should be back to normal, and your CPU temperature problems should be history.

How Hot Should Your CPU Ever Get?

CPU temperature range gauge

Temperatures will vary based on many factors. These factors are the type of CPU, age, size and type of heatsink. That said, these are general CPU temp ranges, deemed acceptable for most consumer-level CPUs.

Below 60°C

Under this temperature, not much is going on in the way of processing power, i.e., the lights are on.

A modern CPU with no overheating issues should idle between 30-35 degrees Celsius. Your CPU may occasionally get over 50°C for light tasks. However, 40°-45° C is also an agreeable idle temperature for most CPUs.

60°-70°

In this range, your CPU is using a moderate amount of power. Your CPU starts to get a little hotter when it uses more processing juice for tasks such as watching videos or using editing software and playing simple pc games.

70°-80°

The average temperature range most pc gamers will find themselves in with graphically intensive games.
Most gamers prefer to keep their temps closer to 70°C. If you hover closer to 80°C, do not panic, as not everyone is going to have the same CPU temperatures across the board.

80°-90°

You’ve entered overclock territory. Ideally, you do not want your temperature to exceed 85°C for any reason. Once your CPU gets close 90°C, it begins throttling in an attempt to cool itself off and prevent permanent damage.

So, you’re not overclocked and regularly exceeding 80°C under load. You can assume that something is not right with either your CPU or heatsink.

90°-100°

Anything over 90°C is too hot for your CPU to function correctly. In this range, you will run into obvious performance issues. The CPU usually throttles 10%-20% at a time, slowing your entire computer down.

Once you get between 95°C and 100°C, it throttles back so much that it shuts down completely. Commonly known as the blue screen of death or BSOD. It is crucial that you find the problem and fix it before you even attempt to check your e-mail.

In this range, you’re sure to shorten the lifespan of your CPU significantly.

Above 100°

At 100°C, you either approach or exceed the max core temp of the CPU, depending on chipset. That is the temperature right before CPU, and maybe motherboard becomes a paperweight.

It is hard to exceed or even meet this temperature. Fail-safes are in place because in the past stupid people did stupid things as with most safety features.

Infographic for an overheating cpu

What Is The Best CPU Temperature Monitoring Software?

Sometimes to identify a problem with your PC, you need to use the right software. That’s where CoreTemp and HWMONITOR come into play. These tools give you the perfect amount of data to help diagnose your overheating CPU.

They are both user-friendly, and incredibly helpful, but what makes each unique?

CoreTemp

CoreTemp by Alcpu

The Alcpu CoreTemp software pulls data from a digital thermal sensor (DTS) which gives temperature data for each CPU core. The CPU cores are arguably one of the hottest parts in the entire PC. You can be confident that any core temp reading that you get from the digital thermal sensor will be on point.

The software is simple and easy to use. You receive the right amount of info about your CPU in an easy to read block style UI. This info includes your CPU model, platform, frequency, voltage, real-time temp readings, and chip specific Tj. Max (Temperature Junction Maximum).

The Tj. Max is the max temperature of a specific CPU model, set by the manufacturer.

If you’re having any issues with your CPU overheating, this is an insightful piece of software to use when you need straight-up data.

HWMONITOR

HWMONITOR by CPUID

The CPUID HWMONITOR software targets and reads all of your computer’s sensors and presents that info in an easy to read, three column, chart. It shows not only your CPUs voltage and temperature, but also your motherboard, graphics card, and hard drive.

Other features of HWMONITOR are the visible real-time use of your CPU cores and fan speeds. You’re also able to see min and max temps, voltage and clock speeds of each component. This data is useful when trying to find a faulty component; in this case your CPU.

It’s so simple to use that your only real options are to save your data, clear your data, and check for driver updates.

Your CPU Heat Problems Are a Thing of The Past

You should now be in a normal CPU temperature range. Have you tried everything in this guide and nothing has worked? Then you didn’t try everything mentioned, or your CPU is already toasted!

These are seriously all problems with CPU overheating on planet Earth. All of them! Unless you live near a volcano. Either way, let us know what worked and what didn’t!