MacBook Pro M3 Max CPU performance capped

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MacBook Pro M3 Max CPU performance capped

I'm using my 16-inch MacBook Pro (Nov 2023, M3 Max) to run a pretty demanding compute job that kept 10 out of the 16 cores fully occupied (i.e., close to 100% CPU use) for over a week. However, yesterday, I noticed a performance cap was suddenly imposed without any prior warning or notification: the 10 processes can now only utilize about 40% of each core, and I need to pause 5 of them to allow the remaining 5 to go back to ~100% CPU use. No matter what I do, I can see in the Activity Monitor that at least 60% of available CPU resources are kept "Idle" at all times.

I thought this may have been due to thermal throttling, so I paused all 10 processes (using KILL -STOP PID) for about an hour to allow the laptop to cool down, then restarted them again (using KILL -CONT PID). This didn't help.

I also noticed that my battery indicator now says "Service Recommended", since my battery capacity is apparently down to 79%. I don't know exactly when this warning first appeared, but I only noticed it yesterday, so I'm wondering if it might be related. That said, I almost always keep my laptop plugged in, and the problem doesn't go away when it's connected to the power adapter.

Is there any way I can remove this performance cap? I guess one obvious solution is to reboot and see if it's still there, but I can only do that once the compute job in question is done.

MacBook Pro 16″, macOS 26.0

Posted on Nov 19, 2025 8:04 AM

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Answer 1

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John Galt

Level 10

155,060 points

Nov 19, 2025 10:03 AM in response to davec-1

I also noticed that my battery indicator now says "Service Recommended", since my battery capacity is apparently down to 79%. I don't know exactly when this warning first appeared, but I only noticed it yesterday, so I'm wondering if it might be related.

Yes it is related, and no it can't be bypassed simply by connecting it to power. The only certain solution would be to replace the battery. Have Apple do it: Mac Repair and Service - Apple Support

The "Service Recommended" warning is not latched and could subside on its own, at least temporarily. Yes it will require a reboot as well as a full recharge cycle.

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Answer 2

John Galt

Level 10

155,060 points

Dec 2, 2025 2:52 PM in response to davec-1

There is nothing incorrect nor irrelevant about the answer I provided. A battery in need of replacement can absolutely, positively contribute to performance degradation, and the only certain solution to that problem is to replace it.

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Answer 3

davec-1 Author

Level 1

4 points

Dec 2, 2025 2:25 PM in response to davec-1

Just in case anyone has run into the same issue, the answer I received here was confidently incorrect. The performance cap was temporary and had nothing to do with reduced battery capacity.

After a few of the long-running processes that I mentioned in my initial post finally finished up, the performance cap went away on its own – again, without any notification, and without me having taken any action (e.g., rebooting). I can now again utilize more than 40% of available CPU resources, which I have specifically checked by using the mpirun utility from the Open MPI library to distribute a program across 12 cores, and verifying that each core is at ~100% CPU use.

My battery indicator still says "Service Recommended" and my battery capacity is still at 79%, so these factors are very much unrelated to the original issue.

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