Mac Pro (2019) is making a loud buzzing/whirring noise

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Mac Pro (2019) is making a loud buzzing/whirring noise

Hi everyone -- appreciate those taking the time to help with this question.

I have a 2019 Mac Pro (3.2 GHz 16-Core Intel Xeon W, AMD Radeon Pro Vega II 32 GB, running Sonoma 14.7).

I recently went on a trip and shut down my system for a few days, and after powering it back up, I'm getting an noticeably loud buzzing or whirring sound.

It continues even after I've put the system to sleep.

I've opened up the machine and used compressed air to clear out the dust. The noise did go away for a few minutes, but then returned.

Wondering what my next steps should be?

Thanks so much for reading.

Posted on May 31, 2026 11:20 PM

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Answer 1

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Theatwar Author

Level 1

58 points

Jun 2, 2026 12:03 PM in response to Theatwar

Thanks so much for the quick replies. It turns out the noise was not coming from the Mac Pro's fans, but rather from the small built in fans that are in two Sonnet M.2 4x4 PCIe cards that were originally purchased in 2019 (https://www.sonnettech.com/product/legacyproducts/m2-4x4-pcie-card.html).

If I can't fix the fans, I do have the option of replacing the Sonnet cards with a newer version that does not use a built in fan. I have a separate question about whether I can move the SSD blades in the old Sonnet cards to the new Sonnet cards and preserve my existing RAID setup -- I asked that in a new post since it's a different topic.

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Answer 2

Jun 1, 2026 9:45 AM in response to Theatwar

The internal fans are the only things inside capable of making such noises. Be sure they are clean and un-obstructed by anything.

It is conceivable that a fan bearing is failing. There should be no play in the fan bearing -- you should NOT be able to wiggle a fan side to side.

The diagnostic has a routine where it spins the fans at maximum and measure the speeds produced by their internal RPM sensors. it is worth running that, if only to listen to maximum fan speed.

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Answer 3

TheLittles

Level 10

206,797 points

May 31, 2026 11:55 PM in response to Theatwar

“Mac Pro (2019) is making a loud buzzing/whirring noise: […]I've opened up the machine and used compressed air to clear out the dust. The noise did go away for a few minutes, but then returned.[…]”

———-

Overheating Mac.

Indeed, it seems to be overheating. So, keep it in an open environment, such as an opened space (the middle of a room), out of direct sunlight, and out of confined spaces. You’ve done the correct troubleshooting step of clearing it out with compressed air.

One this cools, boot it up, and then see if it binge occurs. If it floes, either something in running in the background that should not be. So, open the Activity monitor, and then select Memory tab, sorting it from high-percentage at the top, see what is consuming the most of it,

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