Your Computer's Enemy Number One

Category: Hardware

If your PC or Mac shuts down without warning at random times, there are several possible causes, but overheating is the most likely, and easiest to solve. Read on to learn why heat is your computer's worst enemy, and how to keep your computer from being damaged by overheating...

Signs of Overheating - And What To Do

Electronic components in your computer and other devices generate heat. The harder they work, the more heat they generate. But heat is the mortal enemy of all things electronic. So it's important to be alert to temperature spikes in your computer, and take steps to cool it down when necessary.

How can you tell if your computer is overheating, and what can you do to keep it from frying like an egg? Sudden, inexplicable shutdowns of your computer are often due to overheating. Other symptoms of overheating include declining performance after running processor-intensive tasks for several minutes or hours. Games may run sluggishly, video may skip, and response to mouse clicks may be delayed.

More alarming are sudden software crashes, random reboots, and the dreaded Blue Screen of Death. These symptoms may have multiple causes, but overheating is one suspect that needs to be confirmed or eliminated.

heatsink fan overheating

The computer's BIOS (Basic Input/Output System) detects when the CPU, motherboard, hard drive, or graphics adapter is approaching its maximum operating temperature and shuts things down to avoid damaging that vital and expensive part. If you are experiencing shutdowns, measure your computer's temperatures and do something to lower them immediately.

Temperature sensors are built into many computer components; the trick is accessing these sensors to read temperatures. Unfortunately, Microsoft Windows and Mac OS X do not have built-in utilities to let users read temperatures. You have to find third-party software. Fortunately, there are several free temperature-monitoring utilities. Some can not only monitor temperatures but also do something to lower them.

SpeedFAN is a long-standing favorite temperature monitoring utility. It also monitors voltages in various devices and the speed of the fan(s) which cool your CPU, power supply, and other components. Some motherboards allow users to control fan speeds while others do not; if fan speed can be controlled, SpeedFan will do it automatically to optimize the fan's cooling.

NOTE: Unfortunately, the download link on the SpeedFan website is hard to find. Be sure to click the Download link near the top of the page (next to Screenshots). On the next page, look for "The latest version is..." You'll find the download link there.

Another tool to display temperature readings is Speccy. In addition to that, Speccy also gives you detailed information on every hardware component inside your Windows computer.

Open Hardware Monitor is a free system monitoring program for Windows and Linux computers. It monitors all of the voltage, temperature, fan speeds and other sensors built into your motherboard, including CPU temperature.

Hardware Monitor is a similar utility for Mac computers. It's part of a suite of Mac monitoring utilities written by Marcel Bresink, and it's available on a free trial basis. If you like the software and want to keep it, you can purchase it for under $10 USD.

CoreTemp is designed for Intel and AMD multi-core CPUs. It can monitor the temperature in each core in each processor in your system. It also has a logging feature to record temperatures over variable periods of time.

If you use a fan-speed controller that works with your system, it will provide several benefits. First, it will keep the temperature of your CPU and other components under the critical level, protecting your hardware and preventing shutdowns. Second, it will extend the life of your fan by running it only when it's really needed. Third, it will minimize that irritating noise than cooling fans often make.

Other Overheating Solutions

A good rule of thumb is to make sure your CPU temperature is under 70 degrees Celsius, but each processor has a different safe operating range. I recommend that you see my article What's Going On Inside My PC? to find out what hardware is under the hood, and then search for information on the maximum safe temperatures.

If adjusting the fan speed doesn't bring the problem under control, there are several other possible causes for overheating. Dust is a common cause of overheating. You can buy cans of compressed air to clean the dust out of heat sinks, fans and airflow vents. Crack open the system unit every few months and you'll be surprised at how much dust accumulates there, and how it affects your system temps.

Adequate air flow is important. A tower system should be placed so that its vents are not blocked by desk, wall, or other obstructions. A laptop can be elevated on a cooling pad to allow air to circulate under the machine. (In addition to cooling the laptop, this can keep human "components" from overheating as well.)

It's possible that the fans themselves may need to be replaced. If a fan is noisy, that's a sign that it's not working properly. Some components have built-in fans that can fail. This recently happened to the graphics adapter on my desktop machine. My computer was shutting down unexpectedly, and SpeedFan revealed that the temperature of that component was hitting 120 Celsius (about 250 degrees Fahrenheit). After opening the system unit case, I saw that the fan attached to the graphics card wasn't spinning. As a temporary workaround, I left the case open and cooled things down with a small clip-on electric fan, until I was able to replace the graphics card.

It could also be that the thermal seal between the CPU and the heat sink (which draws heat away) is not good. You can remove the heat sink and reapply thermal grease, but that's beyond the scope of this article. You can find YouTube tutorials on how to do that.

Do you have questions or tips on how to resolve computer overheating problems? Post a comment or question below...

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This article was posted by on 18 Dec 2015

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Most recent comments on "Your Computer's Enemy Number One"

Posted by:

3D Echo
18 Dec 2015

Indeed! Thanks for the monitoring info.

And, heat is the number one enemy of virtually all electronics.

Posted by:

18 Dec 2015

Thanks for addressing this subject. Monitoring the heat is something I have always done since about 1991 or so.
And blowing out the dust is another task.
I now only use a high-powered laptop instead of a desktop.
A while ago, I notice that it was running hotter & slowing down. I removed the screws & opened it up. Full of dust, blew it all out with blasts of air, running like new again.
One, must be carefull opening a laptop, a close by PC repair shop, usually do it right away for a few dollars. I find if they want me to leave it, I go elsewhere. I feel its the same as a flat tire, its a now thing.

Posted by:

18 Dec 2015

A few months ago I moved my desktop pc into a new home office. Since I had already disconnected everything I opened up the case and blew all the dust and cat hair out of it. Then, since the pc tower sits on a corner of my desk, I decided to leave the cover off.
It has been 3 months now and I can see no problems at all. Am I on to something or is a disaster coming around the corner?

Posted by:

18 Dec 2015

I've been using Speed Fan for years. Great help.
However, the mail reason I thought I'd comment is because of the "download" Note. I mainly use to download programs or updates. No added garbage to the download and speed fan is available with a big button you can't miss.

Posted by:

18 Dec 2015

First I would chose a muggy day with poor static.
Then I would unplug my tower and then press the start button and proceed to open it and remove covering around fans etc. Then I would use a vacuum with a plastic tool to suck lint and dust.

Then I read your article on the horrors of opening a computer and the risk of static blowing the whole thing to oblivion. Now I'm wondering if I used up most of my 9 lives and the next will see the end of my computer world.

Posted by:

18 Dec 2015

Thanks Bob , you are 100% right about the overheat problem. for several months I have been struggling with 3 computers that were overheating and I had all the symptom's you described. I must be a slow learner it took me too long to figure out why my pcs were blue screening and suddenly shutting down. I figured there was a heat problem and added fans and on my gamer I added water-cooling. I thought all that would fix the problem. after two processers burning out ,one of which the pump failed . I have learned that adding fans you must make sure you don't overload the fan socket's on the board and you need fans that have enough pressure / cfm to do the job , noting that high speed fans can be noisy. I added a fan controller so those fans can be sped up as needed and this helps a lot with noise ,monitor your temps is a very important thing if you do heavy processing.

Posted by:

Ian O
18 Dec 2015

Have you considered fitting one (or for a gamer a stack of 2 or more) of these little beauties:

You might need an external PSU if your onboard PSU is insufficient as they need 6A each.

Posted by:

John B
18 Dec 2015

Since upgrading to Windows 10 the fan on my laptop runs at high speed when Chrome is running and mid to low speed with Edge running. Before the upgrade I had only occasional fan speed-up with multiple programs running. Any thoughts?

Posted by:

18 Dec 2015

Speccy is great for an instant read on heat levels. By Piriform, those awesome folks that publish CCleaner.

Posted by:

18 Dec 2015

Speccy was great until Windows 10 - which persistently shuts it down!

Posted by:

19 Dec 2015

I also use CPUID HWMonitor. Not adjustable like speedfan but it gives a lot of info like core speed and temperature, voltages and GPU readings.

Posted by:

Old Man
19 Dec 2015

I couldn't find any correct downloads on the link you provided. However, thanks to Dee, I got it from
I also have RealTemp and CPUID HWMonitor. There is very little variance between RealTemp and CPUID core temperatures. SpeedFan only shows temperatures for Core 0, but not Core 1. That single figure also agrees with the other two – there is usually very little difference between the cores.
SpeedFan displays a CPU temperature that agrees with CPUID’s CPUTIN. I’m not sure what that is, since it is 80° F (40° C) hotter than the core temperatures.
I mainly watch the core temperatures, which should not get over 200° F (I don’t usually use Centigrade/Celsius). One feature of RealTemp that I like is that it’s small enough to be moved where the core temperatures show in through the Task Bar without covering the rest of the desktop. That makes it easy to monitor while I’m doing other things.

Posted by:

Old Man
19 Dec 2015

Per my previous post. The reason I’ve gotten heat monitoring software is because of a recent overheating problem. It is not due to dust/dirt around the CPU, air flow or ambient room temperature. I cleaned the CPU and heatsink fins. I haven’t had the side cover on the computer for over 5 years. Except during heat waves (like last August) the room temperature seldom gets over 75° F.
NOTE: I didn’t have any problems during prior heat waves, and the problem began about mid-November.

The overheating problem is primarily when I access sites with a lot of constantly changing ads (something that greatly increased during August). These also cause trouble trying to read the articles – constant freezing the page while the ads reload, and the page jumping up/down due to the different sizes of the ads. Makes it really hard to read the text. About the time I find where I was reading, the cycle starts over again. It also occurs while watching short online videos (like Cats vs. Cucumbers). These cause the core temperatures to jump from about 125°/145° to over 200° - then computer locks up (even the reset button doesn’t work – have to completely power down and let the computer sit a few minutes to cool).

Malware checkers are another cause of overheating. Sophos checks all connected drives, including external ones. Checking the internal drives causes the heat to go way up, while that doesn’t happen when checking the external drives. This tends to point to the internal USB controller chip, which does seem hot. I set a small fan to blow across it, but that doesn’t seem to do any good. Using a desk fan to blow on the entire motherboard had no effect at all (I had to use a clip-on fan for another computer whenever the ambient temperature got over 77° - constant rebooting).

Perhaps you, or your readers, can offer other things to check to isolate the problem.

Posted by:

David Holt
19 Dec 2015

Tried Speedfan; so much crapware in the way I gave up and dumped it.

Posted by:

19 Dec 2015

The fan on the graphics card on my first desktop build quit working so I loosely hung a spare 80mm fan to it with zip ties and plugged the fan into the motherboard.

This worked so well that I didn't bother with buying a new card. It actually kept the card 3°C cooler than the stock fan that quit working.

My oldest Nephew built for me a new desktop PC a few years later as a birthday gift and I gave him my old rig in return.

He currently uses that same graphics card with the hanging fan in one of his PCs to this day.

Posted by:

19 Dec 2015

Oh, I have had heating issues, in the past. Not with my refurbished Dell Optiplex 960, though. This puppy stays quiet and cool.

One reason, I do not have a large graphic card, my graphics is on the motherboard (mobo). Yes, it will eventually, go out, but, I do have a PCI Express slot, to use when that happens. My one issue with my PCI Express slot, since, I don't have a more powerful power supply. only 255 watts - I will need to find a lower grade PCI Express card.

Now, I have been looking for a larger wattage power supply, but, trying to find one that will fit onto the motherboard and within the computer case, is hard to find. This is the one thing, I do hate about Dell or any computer manufacturer - They make things so specific to their criteria, it is hard to replace. In all honesty, this is how they make money and build their business.

I dust and blow out routinely. Push in all of my components, on the mobo, they will vibrate loose many times, check the cables to see, if, they need replacing and overall check out as much, as I can. Routine maintenance for a computer is as important as it is for cars and trucks. Don't check the oil levels and you can easily burn up your engine, right? Same thing with a computer.

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Article information: AskBobRankin -- Your Computer's Enemy Number One (Posted: 18 Dec 2015)
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