NotificationCenter using high CPU or memory on a Mac
NotificationCenter showed an energy impact of up to 4.9 and 80 MB on our Mac, above the browser. What makes it busy, and how to calm it without losing alerts.
What is NotificationCenter?
It is the app behind banners, alerts and the notification and widget sidebar. It lives at /System/Library/CoreServices/NotificationCenter.app and runs as you.
| Sample on our Mac | Energy impact | Memory |
|---|---|---|
| First | 4.9 | 80 MB |
| Later | 2.0 | 78 MB |
In the first sample it was fourth on the energy list, ahead of Google Chrome.
Why is NotificationCenter using CPU?
- Many notifications piled up, each kept and redrawn.
- A noisy app sending notifications every few seconds.
- Widgets in the sidebar refreshing, which also involves chronod.
How do I calm it down?
- Clear old notifications: open the sidebar and use Clear All in each group.
- Turn off notifications for apps that send too many, in System Settings, Notifications.
- Remove sidebar widgets you never look at.
- If it stays high, restart it; macOS brings it back at once:
killall NotificationCenterSee it live
Free Mac's System tab ranks every process by processor use and energy impact, once a second, and marks the ones macOS will not let you quit as protected. See also what energy impact means.
Common questions
Why is NotificationCenter using so much CPU on my Mac?
Old notifications piling up, a noisy app, or sidebar widgets refreshing. Clear notifications and mute noisy apps.
How do I restart Notification Center on a Mac?
Run killall NotificationCenter in Terminal. macOS restarts it immediately.
How much memory does NotificationCenter use?
About 80 MB on our Mac.