Troubleshooting Performance with Activity Monitor on macOS Tahoe
Activity Monitor is the macOS equivalent of the Windows Task Manager. It provides a real-time view of how your Mac's resources are being used, helping you identify why your system might be running slowly or why your battery is draining fast.
Opening Activity Monitor
You can find Activity Monitor in the Utilities folder, or launch it quickly via Spotlight:
- Press Command + Space.
- Type "Activity Monitor" and press Enter.
The Five Tabs
The interface is divided into five tabs, each focusing on a specific system resource.
1. CPU
This tab shows how much processing power each app is using.
- % CPU: Click this column header to sort by usage. If an app is consistently using a high percentage (e.g., over 80-90%) without you actively doing something heavy (like rendering video), it might be stuck.
- System/User/Idle: At the bottom, you can see the total load. If "Idle" is low, your CPU is working hard.
2. Memory (RAM)
This is often the most important tab for general slowness.
- Memory Pressure: Look at the graph at the bottom.
- Green: Your Mac has plenty of RAM available.
- Yellow: You are running out of RAM; macOS is compressing data.
- Red: You are out of RAM, and macOS is using your hard drive as temporary memory (Swap). This significantly slows down the system.
- Swap Used: If this number is high, you might have too many apps open for your physical memory capacity.
3. Energy
Use this tab to find out what is draining your battery.
- Energy Impact: A real-time score of battery usage.
- 12 hr Power: Shows the long-term impact of an app. Useful for finding background apps that drain battery over time.
4. Disk
Shows the amount of data being written to and read from your drive.
5. Network
Shows which apps are sending or receiving data over the internet.
Stopping a Process
If an app is frozen or using too much CPU:
- Select the app in the list.
- Click the X button (Stop) in the toolbar at the top.
- Quit: Tries to close the app gracefully.
- Force Quit: Kills the app immediately (unsaved data will be lost).