“Reduce overheating”. Don’t just put up with your computer running very slow. Your computer could be overheating, and going into “thermal protection mode”.

The “thermal protection mode” is your CPU automatically slowing way down when it is too hot, to protect from destroying the entire computer. You should not run your computer in thermal protection mode, it still has brief yet frequent times at “too hot”, so will eventually ruin your CPU.

What Causes Thermal Protection Mode?

Thermal protection mode is from either the CPU fan not working (whether it is clogged or has failed), or from the CPU thermal grease being old. The thermal grease conducts heat from the CPU to the fan. CPU thermal grease needs to be replaced every few years, before it dries out and no longer conducts heat properly. Yeah, nobody ever told you, right?

How do you know if your computer is in thermal protection mode?

Check your system information apps, to see the temperature of the CPU (look up in search engines how to do it in your version of operating system).

Every CPU model has a recommended maximum temperature, but most should never exceed 100 degrees Celsius, and better not to exceed 95 degrees. Some should never exceed 80 degrees. Check https://www.cputemper.com/maximum-and-normal-cpu-temperature/ for some CPU max temperatures, or the Intel/AMD page for your exact model of CPU. Also, see Normal CPU Temperature: How Hot Is Too Hot For CPU

Note: my computer’s CPU is currently 34 degrees Celsius, but if I run an application that is extremely CPU intensive, such as BOINC, it runs at a maximum of about 85 degrees (briefly, before the fan speed increases cooling). My graphics GPU maximum temperature is 62 degrees, but I don’t do much graphics-intensive work.

What Can You Do To Cool Your Computer?

If you’re comfortable working inside a computer (for example, adding RAM or replacing a hard disk), you could likely learn how to replace your CPU thermal grease, yourself; any computer technician should definitely be able to do it.

While you are replacing the thermal grease, make sure the fan is clean, and the path the dust should flow out of the computer is clear. Gently hold the fan with your fingers so the blades won’t spin, and blow it with compressed air. Never let the fan spin while you are blowing it clean, as it can break, and because the spinning fan can generate electricity that could damage parts. Don’t spray any part in a computer for more than a brief burst, as the air comes out of the can very cold; that cold could damage parts.

Then learn how to check for applications that are constantly using high CPU, which will make the CPU hot. There may be a bug in that version of the program, or there may be a better written program that does the same thing.

If you have a desktop computer, consider Buy a better CPU cooler.

How Do You Replace CPU and GPU Thermal Grease?

Find the instructions for your model of computer, to get to the CPU. Then there is a simple clamp that holds the fan against the CPU. Carefully take off the fan, wipe off or (carefully!) scrape off the old grease, and apply new grease. Then re-attach the fan, and put together the rest of the computer. Same idea for applying thermal grease to your graphics processor.

Replacing the CPU thermal grease on notebook computers is harder than on desktop computers, because you usually have to disassemble the entire computer just to get to the CPU fan; but it is more important to keep your notebook computer running cool, as the notebook is more enclosed and so will tend to run hot.

The thermal paste (aka thermal grease) gets applied to the top of the CPU. You either use a flat edge (maybe a clean popsicle stick or expired credit card) or a tool designed for this, to spread the paste over the entire top of the CPU without going past the edges of the CPU. Or, you apply what the instructions say should be the right amount in a “pea sized ball” at the center of the CPU and when you press the CPU fan in place it will spread the thermal paste for you; you hope it spreads it right.

Figure out for your next computer if you really need a notebook, or if a mini desktop (about 5″ by 5″ by 2″, very easy to open up) will be easy enough to move around. Mini desktops tend to have faster CPUs than mobile computers, and cost less, so getting two monitors and USB hubs, one for home and one for office, will still likely cost the same or less than buying a notebook.

What Thermal Paste Should You Use?

There are several different types of thermal paste to use in computers. (Don’t use one made for use in other equipment, not computers, those could damage computer parts.)

You’ll know you spread the thermal paste right, when you see the CPU temperature staying cool enough.

There are thermal pastes made with metalic particles. Good at cooling, but you have to be careful applying it so you don’t short pins on the CPU.

There are thermal pastes made with carbon, or even artificial diamond particles. These are good heat conductors that don’t conduct electricity, so you don’t have to be as careful to not put too much on the CPU. But of course it is still good to only apply the amount you need, not have it squeeze out past the edges of the CPU.

There are also some sheets of thermal conductor, and you buy or cut it to be the right size for your CPU (or GPU). These normally can be peeled off and used again, if you didn’t get the position exactly right.

Look for a thermal grease that lasts long enough for how infrequently you want to replace the grease. Some good brands last two years, some with different materials last 6 years.

Look for a consistency you like, some are thicker and hard to spread exactly how you want; some are thin and if you apply too much in a ball could spread paste the edges of your CPU onto the pins.

One good review of several good quality thermal pastes is Buy better thermal paste.