Studio Display with Mac mini. Please check if your display fans run constantly, even if both devices are in sleep mode - since macOS 15.4

[txb_811]

I used the tissue paper test

My Studio Display XDR fan runs 3-5 mins After MacBook pro in sleep.
Studio Display XDR Fan runs 3-5 mins when TB5 cable unplug from MacBook, doesn't run until next plug MacBook.

My device
Apple MacBook pro M4 Pro 2024 - Tahoe 26.4.1
Apple Studio Display XDR - Version 26.4.0

 

[macOScurious]

Thanks for testing. Actually this thread is about the older ASD 2022 connected to a Mac mini. From what I have heard from other users the behavior with a MacBook is totally different because your MacBook may be charged while connected to your display.
What would be interesting is an ASD 2026 (non XDR) with a Mac mini, to see if Apple did fix it for the new Display.

 

[Nemensi]

With the default firmware (26.2), the ASD 2026 behaves the same as the ASD 2022. However, with the updated firmware 26.4, power consumption drops back to 0.2 W after DarkWake. The issue could therefore likely be resolved for the ASD 2022 as well via a firmware update.

However, disabling the CoreSmartPowerNap flag should also work for the ASD 2022. I tested this with the ASD 2026 for two days before the firmware update. My Mac Studio remained in deep sleep all night and did not wake up the monitor.

1. Create the directory:

sudo mkdir -p /Library/Preferences/FeatureFlags/Domain/

2. Create a text file powerd.plist with the following content and copy it to the directory:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>CoreSmartPowerNap</key>
<dict>
<key>Enabled</key>
<false/>
</dict>
</dict>
</plist>

3. Disable all periodic wake-up calls:

sudo pmset schedule cancelall

4. Protect com.apple.AutoWake.plist from changes:

sudo chflags schg /Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist

5. Reboot

To check the sleep/wake cycles:

pmset -g log | egrep "\b(Sleep|Wake|DarkWake|Start)\s{2,}"

My other power management settings are:

 standby              0
 Sleep On Power Button 1
 autorestart          0
 powernap             0
 networkoversleep     0
 disksleep            10
 sleep                1
 ttyskeepawake        1
 displaysleep         10
 tcpkeepalive         0
 lowpowermode         0
 womp                 0

Good luck!