Watch which app is hogging the most resources right now

When something on your Mac slows down, the first question is “what?” — which app, which process, which renderer. Activity Monitor will tell you, but it’s organised by metric (CPU tab, Memory tab, Disk tab, Network tab) rather than by what you actually want to know, which is “which thing is misbehaving across any dimension right now.”

Strategies

The four-tab dance in Activity Monitor

The default approach:

1. Open Activity Monitor.
2. Click CPU, sort by %CPU. Note the top entry.
3. Click Memory, sort by Memory. Note the top entry.
4. Click Disk, sort by Bytes Written/sec. Note the top entry.
5. Click Network, sort by Rcvd Bytes/sec. Note the top entry.

If the same process name appears in two or three of those lists, you’ve found your culprit. It works, but you’re bouncing between four views and the picture can shift while you’re not looking.

top with combined sort

A faster terminal approach:

top -o cpu -stats command,cpu,mem,th,disk,netw -n 10

That single view shows you the top ten processes with CPU, memory, threads, disk usage, and network — all at once. Press o while top is running to change the sort key on the fly (try cpu, mem, diskw).

A menu bar monitor with a unified view

The cleanest answer to “across all dimensions, what’s the worst right now” is a tool that shows you all of them simultaneously. Beacon’s menu-bar panel combines per-metric tops in one place.

1. Install Beacon and enable CPU, Memory, Disk, and Network in Settings > Menu Bar.
2. When something feels off, click the readout that looks unusual.
3. Each detail panel shows the top processes for that metric.
4. If the same name appears under more than one — that's your hog.

Pattern recognition

A few common signatures:

• Browser renderer high on CPU + memory + network — a runaway tab. Open the browser’s own task manager (Chrome: Shift-Esc; Safari: Develop > Show Page Resource Usage) to find which tab.
• Slack or Electron app high on CPU + memory — usually a stuck websocket or a bad extension. Restart the app.
• mds_stores high on CPU + disk — Spotlight indexing. Wait it out, or exclude a folder you don’t search.
• backupd high on disk + network — Time Machine. Let it finish; consider scheduling backups to a less inconvenient time.
• com.apple.WebKit.WebContent high on CPU — a Safari tab. Close suspect tabs one by one.

Once you can see all the metrics at once, attribution stops feeling like detective work and starts feeling like reading the room.