Possible BetterDisplay causes full wake and monitor activation during macOS DarkWake

[Trurl101]

On an Apple Silicon Mac running macOS Tahoe 26.1, it looks like BetterDisplay may trigger a full wake during system DarkWake (RTC/maintenance) by creating short-lived UserIsActive power assertions (“Simulated user activity”).

This causes all monitors to turn on briefly (but repeatedly) during DarkWake, even though there is no actual user interaction.

System:
macOS Tahoe 26.1
Apple M1 Max
2 external monitors

There are thousands log entries like this every morning:

2025-12-12 08:28:16 +0100 Assertions          	PID 198(WindowServer) Released PreventSystemSleep "com.apple.WindowServer.PUIDS" 00:00:00  id:0x0x700008806 [System: PrevIdle BGTask DispWake kCPU]          
2025-12-12 08:28:16 +0100 Assertions          	PID 208(coreaudiod) Released PreventUserIdleDisplaySleep "com.apple.audio.context2746.preventuseridledisplaysleep" 03:37:18  id:0x0x50000a784 [System: PrevIdle BGTask DispWake kCPU]          
2025-12-12 08:28:16 +0100 Assertions          	PID 208(coreaudiod) Released PreventUserIdleSystemSleep "com.apple.audio.context2746.preventuseridlesleep" 03:37:18  id:0x0x10000a783 [System: PrevIdle BGTask DispWake kCPU]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Created PreventSystemSleep "Prevent system sleep during an operation" 00:00:00  id:0x0x700008807 [System: PrevIdle PrevSleep BGTask DispWake kCPU]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008808 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 198(WindowServer) Created PreventSystemSleep "com.apple.WindowServer.PUIDS" 00:00:00  id:0x0x700008809 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008808 [System: PrevIdle PrevSleep DispWake kCPU]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000883e [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000883f [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008841 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000883e [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008842 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000883f [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008843 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008841 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:16 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008842 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008843 [System: PrevIdle PrevSleep DispWake kCPU]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008878 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008879 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000887a [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008878 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000887b [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x900008879 [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000887a [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Created UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000887c [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000887b [System: PrevIdle PrevSleep DeclUser DispWake kCPU kDisp]          
2025-12-12 08:28:17 +0100 Assertions          	PID 556(BetterDisplay) Released UserIsActive "Simulated user activity" 00:00:00  id:0x0x90000887c [System: PrevIdle PrevSleep DispWake kCPU]          

Expected behavior:
During DarkWake, BetterDisplay would ideally avoid creating UserIsActive / kDisp assertions so the system can remain in DarkWake with displays off.

Actual behavior
BetterDisplay creates UserIsActive assertions during DarkWake, which appears to:

• escalate DarkWake → FullWake
• start WindowServer
• turn all monitors on

[Trurl101]

There are over 90.000 log rows entries containing "BetterDisplay" between 7:06 and 8:50 this morning of which are around 42.000 like this:

2025-12-12 08:49:31.318683+0100 0x23a160   Default     0x0                  139    8    powerd: [com.apple.powerd:assertions] Process BetterDisplay.556 Released UserIsActive "Simulated user activity" age:00:00:00  id:38654743231 [System: PrevIdle PrevSleep DeclUser kCPU kDisp]
2025-12-12 08:49:31.363541+0100 0x23a160   Default     0x0                  139    8    powerd: [com.apple.powerd:assertions] Process BetterDisplay.556 Created UserIsActive "Simulated user activity" age:00:00:00  id:38654743234 [System: PrevIdle PrevSleep DeclUser kCPU kDisp]

and around 26.000 like this

2025-12-12 08:49:41.625920+0100 0x15d6     Default     0x0                  509    0    NotificationCenter: [com.apple.unc:application] Adding notification to storage: pro.betterdisplay.BetterDisplay:7600BCA2:5928-3595
2025-12-12 08:49:41.625932+0100 0x15d6     Default     0x0                  509    0    NotificationCenter: [com.apple.unc:layout] Re-add pro.betterdisplay.BetterDisplay:2F03719D:40DA-711C, pro.betterdisplay.BetterDisplay with visibility: []
2025-12-12 08:49:41.625937+0100 0x15d6     Default     0x0                  509    0    NotificationCenter: [com.apple.unc:application] Adding notification to storage: pro.betterdisplay.BetterDisplay:2F03719D:40DA-711C
2025-12-12 08:49:41.625946+0100 0x15d6     Default     0x0                  509    0    NotificationCenter: [com.apple.unc:layout] Re-add pro.betterdisplay.BetterDisplay:1952F647:A033-2399, pro.betterdisplay.BetterDisplay with visibility: []

[waydabber]

I have no idea about the second one. The "Simulated user activity" flood is happening for about 10seconds when a display configuration is running (which happens on wake) - it is to prevent the system going to sleep when the display is temporarily disconnected by BetterDisplay (for example when an EDID override is being applied etc - on some systems the instant there is no external display the system goes to sleep which is often undesirable). This should be completely benign.

Interestingly I never saw any issues with darkwake regarding this, so I am not sure about why this happens. From a technical/code standpoint configuration stuff is triggered when a NSWorkspace.screensDidWakeNotification or NSWorkspace.didWakeNotification is received by the app. Both of these are meant to inform user facing apps that the system is fully waking up - these are not issued by the system in a darkwake scenario. Because of this I think what you see is a consequence of the system fully waking up for some other reason.

Do you experience the displays powering on briefly if the app is not running, or it is BetterDisplay that makes the displays come out of standby during the configuration process?

[ultratiem]

it is to prevent the system going to sleep when the display is temporarily disconnected by BetterDisplay (for example when an EDID override is being applied etc)

You could consult pmset's config file and pull that data beforehand, saving you from hammering people's systems that are set to never sleep (like mine for example) from the onset.

man pmset

All changes made through pmset are saved in a persistent preferences file (per-system, not per-user) at /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist

This would lighten the load on system's that are already set to prohibit sleep. Moreover, I would imagine 99.9% of people set that parameter and never touch it again making edge cases almost be non existent.

Just a thought.

[waydabber]

Ok, it's not exactly "hammering", having an assertion does not cost basically anything afaik. Regarding console log recording (when enabled), thousands of log lines are generated within a few seconds in macOS which is entirely normal.

[commentzb3ka]

I just wanted to add exactly this issue breaks Sleep mode on my Mac and makes whole system to wake + external displays to turn on. Usually it takes a few minutes after Sleep is initiated.

EDIT: after further inspection it's any other app that sends notifications to notification centre during sleep causes betterdisplay to wake up external display and the whole system. In my case it was Shortcuts.

Obviously with BetterDisplay OFF nothing triggers wakeups.

[mikepayne02]

Same for me. I have to leave my Macbook unplugged from an external monitor when in clamshell mode and not being used, or else it wakes up every 5 minutes and turns on the monitor displaying the lock screen. Very obnoxious.

[waydabber]

I see - so the issue is about an app sending a notification to notification center during sleep. I believe you then have "Show Notificaions - when display is sleeping" enabled in System Settings, right? If so, then indeed, this will wake the display - the system will therefore notify BetterDisplay about a wake event and the app will indeed initiate the configuration process, which may delay resleep. The app will not unlock the system however and after a while the computer should again go to sleep (after the configured time).

[ultratiem]

Notification Centre does not apply to all notifications. Apple reserves system notification control and a user cannot disable it. For example, when AirPods auto-connect, when they drop below 5% battery, or when Siri is activated, macOS will force the screen to wake. This occurs regardless of BetterDisplay.

The 3 settings are (this is Sequoia but its the same in Tahoe):

The first should silence all notifications. The second, only when the screen is locked. Which may never occur as some users may elect not to lock their screens (I do not) and should note the screen being off does not mean it is locked. The third option useful for presentations and meetings so you don't broadcast your notifications.

Sadly, this is just an Apple thing (as it occurs on iOS too). There is no way to silence some notifications in macOS.

But from what I understood, this isn't that. But rather BD triggering a wake by it self. At least, that is how I read the original BR.

[waydabber]

Maybe. However I could not reproduce BD triggering wake (the code works the opposite way - a system wake message triggers BD to do some actions).

The PreventSystemSleep and UserIsActive console logs are triggered in very specific circumstances (see the comment below) and happen at wake (as a consequence) only if certain configuration protection, connection management and EDID override operations require it.

[waydabber]

Investigating the issue more, I have trouble reproducing the problem. My earlier comment about the app keeping the system awake on a simple display configuration running was untrue (I remembered wrong, sorry about that).

The app actively prevents system sleep briefly (which causes the log reports in the initial comment by @Trurl101) in the following circumstances:

• A display configuration override is being activated (initiated manually from the app's Settings after configuration editing)
• Display is being connected or disconnected by the app (using software) - this may happen on wake is a feature requires it (like keeping a soft-disconnected display disconnected).
• VMM7100 reset (rare + very specific)
• Mode change - this may be invoked on wake if configuration protection requires such a thing
• color mode change - this may be invoked on wake if configuration protection requires such a thing
• HDR mode change - this may be invoked on wake if configuration protection requires such a thing
• EDID override - this may be invoked on wake if auto-apply is configured and is required

So the question @mikepayne02, @commentzb3ka, @ultratiem, @Trurl101 is whether any of the following features are used and if they are, how. As these may trigger extra sleep-prevention on a wake when the system reports a wake event to the app (I don't think darkwake is included, but the "Show Notificaions - when display is sleeping" setting in System Settings certainly is, as that will turn the display on):

• Configuration protection (resolution, refresh rate, color mode, HDR status)
• Some connection management feature (active soft-disconnect, disconnect built-in with external display, etc)
• EDID override (with auto-apply)

If this is a pain point, I might need to further think about this.

Thank you!

[waydabber]

Those, who have this issue could try running the app with logging /Applications/BetterDisplay.app/Contents/MacOS/BetterDisplay -v so we can see some context on what is happening.

The app clearly logs (System sleep prevention in effect for..., Prevent display sleep in effect because of device with tagID..., etc)when it prevents system sleep and when it finishes with that (Prevent display sleep removed for tagID, System sleep prevention causing ... simulated user activity events is now over) + the app logs show the context, why it would do such a thing.

(note: the logs are available in the console as well when the app is running normally, here is how you can filter for it: https://github.com/waydabber/BetterDisplay/wiki/Enable-console-logging#look-at-the-console)