MacBook is overheating. What to do?

A few months ago I installed iStat Menus, a computer component monitoring application. With it, I wanted to figure out why my MacBook Air sometimes slows down for no apparent reason. It turned out that the processor temperature is kept at 90 ° C even in winter, and in some places it rises to 99 ° C. The MacBook is overheating, which causes the system to brood.

iStat displays various system indicators in the top menu

The new MacBook Pro overheats and throttles. Found a budget solution

By adjusting the fans on the MacBook Pro, I was able to get the i5-1038NG7 processor to run 200 MHz faster. This increased its productivity by 7%. Here’s how to do it.

How replacing thermal paste saved my MacBook Pro from overheating

After replacing the thermal paste, my MacBook Pro stopped overheating and the processor ran at maximum speed for the first time. As a result, the performance of the laptop increased by 15%. I tell you what I did for this.

The MacBook Air hasn’t been cleaned in 5 years, so I figured it would be good for it to clean and replace the thermal paste of the processor.

For fun, I also put iStat on my friend’s MacBook Pro. This laptop is clearly noisy and warms up more than expected. It turned out that even under natural load, the processor heats up to 104.8 ° C, with a maximum allowable temperature of 105 ° C. The last time the laptop was cleaned was 6 months ago, then the thermal paste was changed.

Well, since such a thing, I decided to change the thermal paste on my MacBook 12 ″. It overheated more than once in the summer, up to and including shutdown.

As a result, there were three laptops on my desk:

  • MacBook Pro 13 ″ on Core i7-3520M, 2.9 GHz (late 2012)
  • MacBook Air 11 ″ on Core i5-4250U 1.3 GHz (mid 13)
  • MacBook 12 ″ on Core M-5Y31 1.1. GHz (late 2015)

I cleaned all these laptops and changed the stock thermal grease to Thermal Grizzly.

One gram of Thermal Grizzly thermal paste was enough for three laptops and a Nintendo Switch

If your laptop is still under warranty, then if you experience symptoms of overheating, you need to take it to a certified service center. In all other cases, proceed as appropriate. But you will definitely need straight arms, a set of screwdrivers and tweezers.


To disassemble the laptop, you will need a variety of screwdrivers and tweezers. I personally use the iFixit Pro Tech Toolkit ($ 60). The set is cool but expensive. Here is its budget counterpart from Aliexpress ($ 16).

My toolbox from iFixit

Testing technique

To see the effect of replacing thermoplastics, you need to take the “before” and “after” indicators. For this we need the Prime95 v26.6 and Blender Benchmark packages.

READ ALSO: How To Test Mac Performance: A Selection Of The 7 Best Utilities

To start testing in Prime95, click on Option Turture Test … from the menu. In the window that appears, select Samll FFTs, and then Run

Blender Benchmark is an add-on for the package of the same name for rendering and animation. In fact, this is the same Blender, only it has replaced the entire interface with a window with two buttons: Quick Benchmark and Complete Benchmark. In the first test, 2 scenes are rendered, in the second, six.

To start Blender, just click Quick Benchmark

I put each laptop under maximum load for 15 minutes and recorded the maximum temperature. After that, I let the laptop stand on for another 15 minutes and recorded the temperature when idle.

All tests were carried out under a clean account to neutralize the impact of installed programs.

I monitored the temperature and throttling of the processor using the Intel Power Gadget utility. Fan speeds and component temperatures via iStat Menus. I wrote about how to interpret the results of Intel Power Gadget in the review of utilities for testing Mac.

Replacing Thermal Paste in MacBook Pro

MacBook Pro disassembly instructions, 2012.

The 2012 MacBook Pro has a relatively simple design where it is difficult to damage anything. Moreover, it has a large number of screws and internal connectors.
To change the thermal grease, you need to completely remove the motherboard. It takes a lot of time and work with tweezers.

Preliminary testing has shown that the MacBook Pro overheats a lot. Even when compiling a project in Xcode, the processor warmed up to the maximum allowable value of 105 ° C. After that, throttling occurred, in which the frequency decreased from 3.4 to 3.2 GHz.

Throttling is when the processor itself lowers its maximum frequency in order to stay within the allowed temperature range.

It turned out that the thermal paste was changed inaccurately the last time. Excess is visible on the crystal substrate, and there was no thermal paste on the corners on the crystal itself.

Thermal paste was not neatly applied and did not cover the entire crystal. The trace from the air pocket is clearly visible

Last time, the paste was applied in a thin layer, previously smeared over the crystal. It is better not to do this, because air will remain between the crystal and the radiator. This explains why parts of the crystal did not adhere to the heatsink.

Smearing thermal paste leaves air pockets between the processor and heatsink

I removed the factory thermal grease and applied a new stripe. When applied in a strip or drop, the paste squeezes air out and spreads evenly over the crystal.

A drop or strip of paste squeezes out all the air and spreads evenly

Replacing thermoplastics in MacBook Air

MacBook Air disassembly instructions, 2013.

MacBook Air has a simple and straightforward design, so you can change thermal paste even at home. You only need special screwdrivers.

There is no electronics on the bottom cover of the laptop, it is simply removed and you get access to the cooling system. To remove the cooler and radiator, it is enough to disconnect one connector and unscrew six screws.

In a preliminary test, the MacBook Air showed temperatures of 93 ° C, which periodically bounced to 99 ° C. MacBook Air overheated and fell into a stupor.

The complete thermal grease is dry and does not completely cover the crystal. There should be no thermal paste on the PCH chip

The chip that is not covered with paste is called the Platform Controller Hub (PCH), or “south bridge”. At first I confused it with a GPU and decided to coat it with thermal paste. But Igor Mamontov suggested tweeted that it could be the south bridge.

And so it turned out. The PCH heats up less than the processor, so you really don’t need thermal grease there. I removed it and the PCH temperature dropped by 7 ° C in iStat Menus.

Replacing thermoplastics in MacBook 12 “

MacBook 12 disassembly instructions, 2015.

In 99% of cases, I would recommend taking such a MacBook to a service and not trying to do something at home. It has many small and fragile connectors that can be easily damaged. And to get to the radiator, you need to completely disconnect the motherboard and turn it over.

In the control test, the MacBook warmed up to 90 ° C, held at this temperature for 5 minutes, and then throttled and the processor frequency dropped from 2 to 1.9 GHz. By the way, my throttling was not as strong as in Linus’s video.

In most cases, this MacBook’s case doesn’t get warm at all. It feels like you’re working on a big iPad. But last summer, I got into trouble on more than one occasion when I tried to work with my laptop outdoors in a coffee shop or under an umbrella on the beach. I constantly got a warning about overheating, and the laptop was shamelessly slowing down.

In the summer, the MacBook could only be used indoors. On the street, he instantly overheated

The MacBook has passive cooling and no fan. The processor and graphics chip are covered with an aluminum lid and a thick layer of thermal paste between them.

The processor is covered with thick thermal paste, which completely dried in two years

So much thermal paste indicates the presence of a gap between the heatsink and the chip. And so it turned out. Usually, such gaps can be removed with a copper plate of the correct thickness. But I did not bother, in general, there are no complaints about the laptop, with the exception of summer overheating. Normal and thick thermal paste should handle this.


Oddly enough, all three laptops were practically clean inside. Therefore, cleaning the heatsinks and cooler from dust, if it did, had a minimal effect. It even better shows the difference between Apple’s slurry and normal thermal paste.

In all cases the paste was applied inaccurately. Its quality can be judged by the graphs.

When tested, the room temperature was 21 ° C

MacBook Pro finally got out of the dangerous temperature zone, and the fan speed dropped from 6200 to 4400 rpm. It feels like heaven and earth. The laptop stopped whining completely in XCode, Chrome and small games. And even a long warm-up of the case with a maximum load spins the fans only up to 4400 rpm. But this only happens when exporting video to Final Cut. Throttling also disappeared. Now the processor is stable at 3.4GHz.

If the fans are forcibly turned up to 6200 rpm, then the temperature drops from 95 to 86 ° C. This means that there is a margin of safety for the summer heat.

MacBook Air stopped overheating in games. After replacing the thermal paste, I was unable to heat it up so that the fan would spin up by more than 2000 rpm. Although previously overclocked to 3200.

MacBook 12 ″ got rid of throttling. It no longer lowers the frequency of its processor when it overheats, so performance does not drop even with prolonged load. Oddly enough, its passive cooling system responded well to replacing thermal paste. The difference with the complete slurry is 12 ° C, I hope this will help him out in the summer.

Temperatures can be reduced even further by manually adjusting the fan speed curve in your MacBook. I wrote about this in a new article 👇

The new MacBook Pro overheats and throttles. Found a budget solution

By adjusting the fans on the MacBook Pro, I was able to get the i5-1038NG7 processor to run 200 MHz faster. This increased its productivity by 7%. Here’s how to do it.

How replacing thermal paste saved my MacBook Pro from overheating

After replacing the thermal paste, my MacBook Pro stopped overheating and the processor ran at maximum speed for the first time. As a result, the performance of the laptop increased by 15%. I tell you what I did for this.

Should you do this at home?

Yes, if you run out of warranty, you have interest, skills and tools. But it’s better to take your laptop to a normal service center. Perhaps even with your own tube of thermal paste. This is especially true for laptop models after 2015.

My experience has shown that replacing the stock gum with a normal thermal paste is guaranteed to throw off 5-10 ° C and a couple of thousand fan revolutions. The laptop will be able to run longer and quieter at maximum frequency.

Apple service center

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