Windowserver high CPU after sleep

I have found that the notification centre and notification widgets on the desktop (e.g. clock etc.) cause consistent high cpu usage (e.g. most of an efficiency cpu on a MacBook Pro M1 Max - this would show up as 14-20% in Activity Monitor). Removing all widgets immediately drops it to 2-4%. Note these measurements are with no apps running: things like chrome (and google meet etc.) can use a lot of CPU, though chrome has improved over time.

I have the same problem. My setup is a MacBook 14 with M1 Max and 2 Studio Displays. One of the displays is mirrored via HDMI. When the device is woken up, it happens that the Windows server has a very high CPU load (80%) and does not return to normal. As soon as I stop mirroring, the CPU load normalizes again at around 15%.

Did this start to occur recently?

I noticed that you have installed tencent and realvnc a few days ago. Maybe these are not updated for Sonoma and cause some issue?

I was not familiar with tencent lemon and it is a "cleaner" application. FWIW, Macs don't need any "cleaners". They sometimes clean all too well, causing system issues. Was there any particular reason for installing this?

Your mac can work as both a vnc client and server with just the built-in software. Maybe there is some extra functionality provided by realvnc, I don't know. I regularly connect to a remote mac with just built-in software.

And finally, I noticed OpenVPN. Again, no idea to the purpose, and it may be a valid one, but I have to warn about the false sense of security often promoted by public vpn applications... Public VPN are anything but private

I can only state my experience, for me it is now mostly 4% or less, but does go up to 7 when windows are being updated i.e. safari/chrome (e.g. me typing in this reply). Do you have any notifications hanging around? Closing those might help.

Guide: How to solve Yosemite memory leaks… - Apple Community

About 2hrs since I followed the exact instructions, WindowServer process was at 80%+ before I started. So far, stable at about 1-5%.

MacBook (Retina, 12-inch, Early 2016)

8 GB 1867 MHz LPDDR3

MacOS Monterey 12.7.5

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This bug only happens when mirroring is turned on, not when extending desktop to 2nd monitor. My laptop screen broke, so I used mirroring and set external display for main display. I use MacOS 14.1.2, M1 MacBook Air connected with DisplayPort cable to a Samsung 4k monitor.