A few months ago I got a 16-inch MacBook Pro (A2141) with 32GB ram and Core i9 (I9-9980HK) 2.4 GHz processor.

My problem is that that it overheats very quickly and drop the performance of the CPU to the ground. I installed Intel Power Gadget for investigating and turns out, just after a few minutes of heavier workload (clean install a bit larger maven project) get so hot the system limits the maximum core clock speed to 1GHz. When this happens the mac feels very slow and janky and even the most basic things can take uncomfortably long.

I heard that this series of MacBook Pros with Core i9 has thermal issues but this seems ridiculous. I already bought a Cooler Master A200 laptop cooler and it's helped a bit, but it still doesn't feel right.

Does this MacBooks has THAT bad thermal problem, or should I take mine for a cleaning? I also read that a repaste would help a lot. Do Apple authorized services allowed to perform repaste and cleaning? I could not figure it out from official websites. Does the repaste/cleaning at a non-Apple authorized service spoil the warranty?

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    Is there any process going on that consumes a lot of CPU cycles? What is Activity Monitor showing when this happens?
    – karolus
    Feb 6, 2021 at 18:51
  • Did you get your Mac new or used? Battery issues can make the whole Mac be throttled to the levels you are describing. How is your battery health? The CoconutBattery app can help you with that. What exactly are your CPU and other system temperatures under load when throttling begins, and after it stabilizes on 1GHz for a few minutes? Intel Power Gadget and Macs Fan Control apps can help you with that. Can you upload screenshots of the graphs? Feb 6, 2021 at 20:42
  • Also important: is your macOS version up-to-date? It's always important to keep your Mac up-to-date on the latest updates and bug fixes. There was a bug on an older version of macOS which caused heavy throttling on these Macs and was fixed by a software update. Feb 6, 2021 at 20:44
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    I know how you feel, I did the same tests you did (and many more) before changing the battery. My MBP had great performance and no throttling (even turbo boost to 4.2GHz!) whenever I had a huge fan blowing fresh air directly on it. I also put it in the fridge: no throttling. The results were even better when not plugged in (running on battery). My guess is the issue lies on the voltage regulation module (VRM). The battery may not be providing sufficient voltage. As the VRM maxes out to compensate, it quickly heats up, and sends a signal to the CPU to throttle so that the thermals go down. Feb 7, 2021 at 0:55
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    Quick update: my job has provided me with a very similar MacBook Pro to yours (2019 16", less RAM though). It is brand new, I unboxed it myself. I'm using all of my development tools, virtual machines and containers at the same time, lots of open apps (restored backup), while using 3 monitors (Mac's monitor plus two 4K monitors plugged to it) and the dedicated GPU (5300M) is always turned on. I've worked all week on it. Couldn't make it thermal throttle as yours. Avg clock speed when stress testing it for 15 minutes is 3.0GHz, CPU stable at 75ºC. It's running macOS Big Sur (currently 11.2.3) Mar 16, 2021 at 19:31

3 Answers 3


AppleInsider tested the 2019 Core i9 2.4GHz MacBook Pro 16" and found that it could maintain 3.19GHz under sustained load. This and many other sustained load benchmarks demonstrate that your issue is not normal.

The easiest thing to do is bring it to Apple so they can fix it. If you want to know more, keep reading.

I think some repairs would actually require Apple Authorized Repair shops to reapply thermal paste, so I guess they are allowed to do it. They are also authorized to clean the Mac's internal components, and will often do that for all repairs requiring opening the computer.

Any repairs done outside Apple Authorized Repair shops could void your warranty if done incorrectly, but there isn't anything inside your Mac designed to tell Apple it's been repaired by someone else. So unless they screw up, I think it won't void your warranty. In my opinion, I'd rather not risk it, specially for replacing parts.

Intel clock speeds

1GHz (and sometimes 800MHz) is the absolute lowest clock speed the CPU in Macs like yours can go. Throttling down to the lowest clock possible under Standard Ambient Temperature and Pressure (SATP) is not normal. Intel/AMD/x86 notebooks often throttle to some degree, but extreme throttling is usually a sign of a deeper issue. The expected behavior on well designed computers (such as the 16" MacBook Pro) is to, at most, stay close to the base clock when under sustained load (CPU-only).

Your Mac has a base clock of 2.4GHz. Based on my experience with Macs and your model's benchmarks, I think normal values for it on SATP would be 2.4~3.2GHz under sustained load (CPU-only workloads, discrete GPU disabled), or 2.0~2.4GHz under sustained load for workloads that heavily use GPU in addition of the CPU.

Here are common things you can do to troubleshoot your issue. Remedies potentially fix the issue. Workarounds might improve your situation, but are unlikely to actually fix it. I recommend trying the remedies.

Check if you have the latest updates

It's very important to keep your Mac's Operating System (OS) up-to-date. Updates include bug, performance, reliability and security fixes and improvements. It also includes new features. Apple has previously fixed thermal throttling for some MacBook Pros in a software update.


  • Update macOS to the latest version

Check the temperatures

Thermal throttling is caused by aggregate component temperatures above the computer's thermal budget. This usually means the CPU and GPU because they are the most power-hungry parts, but is not limited to them. High battery temperatures or high VRM temperatures can also make the computer throttle.

The CPU and GPU can withstand temperatures as high as 100ºC, but that's the limit. Macs usually prefer keeping it to lower temperatures such as 85ºC under sustained load. If your Mac's CPU is at around 85ºC or more while throttling after a long time, it's possible the issue is the CPU's own temperatures.

If the CPU temperatures are not that high, check the GPU temperatures, which also present numbers similar to the ones mentioned above.


  • Check if the fans are working. 15"/16" Intel Macs have 2 fans, whereas 13" and smaller Intel Macs usually have 1 fan.
  • Clean all computer vents and fans, carefully removing dust and extraneous objects that are blocking airflow.
  • Carefully clean then replace the thermal paste for the components that originally had thermal paste on them (usually CPU, but could include GPU).

Workarounds (I do not recommend. They will only alleviate the issue, not fix it):

  • Use an utility such as Macs Fan Control to manually adjust the fan curve or max out the fans on your Mac in order to delay throttling.
  • Use an utility such as Turbo Boost Switcher to disable Intel Turbo Boost. This could delay throttling but will make no effect after it begins throttling.

Closed operation and airflow

Macs can operate with the lid closed by using an external monitor and peripherals. The MacBook cooling design inputs air from the sides and outputs to the back. Cooling design


  • Make sure your Mac's airflow is not blocked or hindered by objects, fabric or walls in close proximity.
  • Avoid placing your computer on top of fabric, in particular if the fabric is designed to warm up such as carpets or blankets.


  • The higher your ambient temperature, the more throttling your computer could exhibit, so move to an air conditioned room if possible.
  • Try opening the lid and see if there's any difference in behavior.

Battery aging

Portable computers use batteries to continue working when not plugged to a power outlet. The battery is a consumable part of the computer, and its performance degrades as it ages. Apple has developed specific features to help with that.

The ability of a battery to supply the required voltage for the processor and other components is affected by its age.

Quoting Apple:

All rechargeable batteries are consumable components that become less effective as they chemically age.

As lithium-ion batteries chemically age, [their] ability to deliver maximum instantaneous performance, or 'peak power', may decrease. [...] One attribute that affects this instantaneous power delivery is the battery’s impedance. A battery with high impedance may be unable to provide sufficient power to the system that needs it. A battery's impedance can increase if a battery has a higher chemical age. [...] These are characteristics of battery chemistry that are common to all lithium-ion batteries in the industry.

When power is pulled from a battery with a higher level of impedance, the battery’s voltage will drop to a greater degree. [...] The power management system determines the capability of the battery to supply this power, and manages the loads in order to maintain operations.

As the battery's ability to supply a consistent voltage is diminished, the Voltage Regulator Module (VRM) will have to work a lot harder to convert that to a usable, constant voltage for your Mac's circuitry. This in turn can make the VRM overheat, which could cause your Mac to throttle other components to the levels your Mac is experiencing in order to dissipate the heat.

Apple, iFixit and many others recommend changing the battery when its health drops below 80%, or when its cycle count goes over 1000. Your Mac will automatically tell you when your battery reaches these thresholds, but you can use CoconutBattery to manually check the battery health of your Mac. If it's close to 80% or lower and you have already checked the other things mentioned here, this could likely be the cause of your computer's extreme throttling.

80% is not a magic number. Battery aging is a complex chemical process also affected by temperature, and your battery may naturally have its performance diminished before or after this threshold. Apple is very good at managing (and even masking) battery aging by taking steps to remedy and keep the device working reliably for a very long time. I've had Macs with over 6 years old batteries still working fine.

This means your Mac's battery is probably fine and could still be used for many years. But the Intel Core i9 and the discrete AMD GPU are very power-hungry devices that draw a lot of instant power from the battery, potentially dropping the voltage, regulated by the VRM. The i9 alone draws 45W at 2.4GHz. So if your Mac's VRM is overheating due to the battery aging, perhaps it would be in your best interest to replace the battery in order to have better performance.


  • Replace the battery on an Apple Store or authorized repair shop.
  • Never use generic or counterfeit batteries or chargers on any devices you own. Counterfeit batteries and chargers have high risk of fire, swelling and irreparable damage to your devices, amongst potentially reduced battery life, increased aging and incompatible power draw. It's just not worth the risk and could end up costing a lot more.

Using the computer plugged in

It's possible that the battery will naturally heat up as it charges. This could lead to an additional degree of throttling.


  • Try using the computer unplugged and see if temperatures improve.
  • If you want to keep it plugged in, fully charge the battery before starting your workload

Discrete graphics

15" and 16" Intel Macs have discrete graphics in addition to the CPU's integrated graphics. The discrete GPU is a powerful chip that competes with your CPU and other components for the computer's thermal budget. The thermal budget is the total capacity of your computer's thermal design to dissipate heat, usually measured in Watts.

When the discrete GPU is doing heavy processing, it's expected that the CPU will exhibit more throttling than if you were only using the CPU. Macs automatically switch between discrete and integrated graphics depending on what tasks they are running and whether your Mac is running on battery or plugged in to achieve a balance between performance and battery life.

You can check this opening the Energy tab on Activity Monitor. Activity Monitor Placa gráfica = Graphics card. Integrada = Integrated. Sim = Yes. Não = No

  1. Shows whether your Mac is using Integrated or High Performance graphics
  2. Shows which apps are using the discrete GPU

There's also the free utility gfxGardStatus that constantly shows an icon with the current GPU on the menu bar and can display notifications when the GPUs are switched, as well as which apps are using the discrete GPU.


  • Close apps that are using the discrete graphics when you want higher CPU performance.

External displays

Intel Macs with discrete graphics often use the discrete graphics to drive external displays connected to them.


  • If you don't need it, disconnect the external display

Apple Diagnostics

There's a simple tool that comes with Macs and is able to catch a few issues: the Apple Diagnostics tool (there's more than one link for it). Reboot your Mac holding the D key or or follow the instructions provided on the links. Running the tool will give you a simple result that can be used to find obvious problems with your Mac and (optionally) request support. Apple Diagnostics This tool is not a substitute for bringing your Mac to an Apple Authorized Service Provider (AASP), where Apple runs a complete suite of tests that is able to catch more issues than this diagnostics tool.


  • Run the tool and see if it finds any issues.

Clean Operating System install

If everything failed and you think you have a software issue you are not willing to troubleshoot, you can try to do a clean macOS install. Before trying that, backup any data you want to save. This operation will completely erase everything that's on your Mac's internal storage and you will not be able to restore any data lost after formatting if you don't have a backup.


  • I disagree with taking a “hardware-first” approach to diagnosing this issue. There has been no data yet from the OP to indicate that this isn’t a software issue. We need to examine top output and see what’s responsible for high resource usage first.
    – pion
    Feb 8, 2021 at 0:38
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    @pion The first topic on my answer and some workarounds I presented were software-related. I've asked many questions to the OP, I guess 50-50 for software and hardware, but OP didn't answer. Nonetheless, it doesn't matter if there's software stressing all of his resources, because stress tests done by 3rd-parties using his Mac model show his hardware should not throttle so heavily on SATP, regardless of use. Therefore it's very likely a hardware issue. He could format and try again, but given he said his battery health is at 83% and better cooling fixes the issue, it's likely that won't fix it Feb 8, 2021 at 12:19
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    Disconnected the external display, and my thermals got way better, I'm almost satisfied with the result given the typical workload during my typical workday. But to me, this falls under "you hold your device wrong" given this is a 3000 dollar plus "professional" device. This is ridiculous, I regret choosing this over Razer Blade 15 Studio. Anyway thank you for the help! Feb 8, 2021 at 21:32
  • This means that there is a software bug in the OS (possibly the GPU driver, display MUX, GPU firmware, or Intel microcode). The point is that your hardware is very likely fine and you should report this to Apple so that they can fix the underlying issue and include the fix in a software update.
    – pion
    Feb 9, 2021 at 4:33
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    @Syngularity your Mac is presenting the same behavior my Mac did. with almost same battery health. When new, my Mac didn't have this issue, I worked all day on it with external display for years and had no issues. The issue started when battery health was around 84%, getting worse as the battery aged. Then the external display would almost always make it unusable, and doing these workarounds would improve the issue, just like yours. If it was my Mac, I'd check the battery, just like I did. Just Google all the benchmarks for your model. This behavior is not normal, you're not holding it wrong Feb 9, 2021 at 22:40

There might be a problem with your voltage regulation module (VRM). If the battery doesn't provide sufficient voltage, the VRM will try to compensate by maxing out. So it heats up, and CPU throttles, so that the thermals go down.

  • Mine is 1.5 years old and I didn't leave it connected to the charger every time, also it shows "Battery Condition: Normal". I agree with you that it is most probably VRM, but not sure if it is connected to the battery or not.
    – mihatel
    Jan 13, 2022 at 7:34

My MBP throttles to 2.6GHz flat when connected to a Baesus 100W usb c power supply. Unplug the power supply and it jumps back to 4.4 GHz. Interesting behaviour of the VRM.

  • Found the issue: User error. There is a setting in System Preferences > Battery > Power Adapter, low power mode. This was enabled which caused the laptop to switch to lower power mode when plugged in. Low power mode throttles the CPU. Jul 6 at 15:02

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