macOS 26 Tahoe - WindowServer taking chunks of CPU and Memory

Question

Level 1

17 points

macOS 26 Tahoe - WindowServer taking chunks of CPU and Memory

MB Pro Apple M2 Max | 96 GB | Tahoe 20.0.1

WindowServer is consuming a significant amount of Memory and CPU, as indicated by Activity Monitor. This has impacted using other large resource apps like Adobe Premiere Pro, essentially shutting down efficient usage of these apps (laggy performance, video stuttering, etc).

I have tried multiple solutions suggested, including minimizing or closing other running apps, restarting, clearing cache, etc. Left the computer running overnight with no apps other than Finder active, and WindowServer still came in at more than 700 MB of memory. This will balloon much higher if I crank up some apps like Adobe programs, browsers, etc.

Frustrating because this MB Pro kicked butt on these programs on prior OS's and I am reluctant to go through the process of rolling back to Sequoia.

Posted on Oct 7, 2025 5:24 AM

Reply

Answer 1

Top-ranking reply

neuroanatomist

Level 9

55,881 points

Oct 7, 2025 7:30 AM in response to R_N_C

See if the problem is present when you boot in safe mode, which disables 3rd party extensions and performs some system cleanup.

Start up your Mac in safe mode - Apple Support

If that corrects it, reboot normally. Personally, the windowserver process on my 16" M4 Pro MBP is generally ≤2% CPU (I have a large 5K:2K display and I use Spaces with 5 desktops, so I have lots of window open).

Reply

Answer 2

Nov 13, 2025 1:09 PM in response to R_N_C

You likely have an app running that is built with electron. It's a framework for building desktop apps with JavaScript. Electron has fixed it but developers need to update their apps in turn. Hopefully whatever app is causing it for you will be updated soon; in the mean time, remove 3rd party apps.

Reply

Answer 3

Bouscram

Level 1

9 points

Oct 9, 2025 7:49 AM in response to R_N_C

I had the same issue with an Intel Core i7 MacBook Pro. Starting in Safe Mode, then restarting normally seems to have removed the problem. A bit weird, but I guess it cleared something...

Reply

Answer 4

Nov 10, 2025 5:17 AM in response to R_N_C

I got the same Problem on my i5 Macbook Pro 2020 (4 thunderbolts). Safe mode helped to reduce the numbers of crashes caused by WindowServer (as did the update to 26.1) but they still frequently happen. Not only using adobe or MS but also backups with a WD and apple programs are taking a high amount of CPU and GPU. This wasn't the case at all with Sequoia...

Reply

Answer 5

rémy66

Level 1

8 points

Oct 30, 2025 2:17 AM in response to neuroanatomist

Hello, even when started in Safe Mode, as soon as I work on a PDF with “Preview”, the CPU usage climbs above 20% and the GPU usage above 8%.

I am working on a Apple M3 Pro

Do you have any input on how to solve this issue ?

Reply

Answer 6

Oct 30, 2025 11:45 AM in response to rémy66

Odd, and unfortunately I'm not sure what to advise. I just opened a set of ~40 PDFs in Preview, CPU usage by Preview jumped (the blue spike at the left below) to ~200% then ran at 130-160% for a minute or so (presumably as they were all rendered) then dropped down to 5-10%. Even at peak, the collective cores were 70-80% idle, once the rendering finished it was back up to 95% idle (with all the PDFs still open).

Reply

Answer 7

Oct 7, 2025 6:41 AM in response to R_N_C

Same here. I'm almost unable to user iTerm for example. And others too. The WindowServer remains using a lot of cpu.

Reply

Answer 8

Oct 30, 2025 3:50 AM in response to rémy66

Is there a problem? The CPU and GPU % usage sums the cores, your Mac has at least 11 CPU and 14 GPU so you’re using 20% and 8% of a possible 1100% and 1400%.

Reply

Answer 9

rémy66

Level 1

8 points

Oct 30, 2025 11:34 AM in response to neuroanatomist

The problem isn’t the %CPU usage itself, but the lag when editing PDFs in Preview or using Excel.

Reply