Find what's slowing your Mac down right now

Your Mac is dragging — apps switching slowly, the cursor stuttering, fans audible. The instinct is to restart, but you’d actually like to know why, partly to fix it and partly so it doesn’t happen again. The trouble is that “slow” can mean CPU, memory, disk, network, or thermal throttling, and Activity Monitor makes you check each one separately.

Here’s how to triage it fast.

Two paths

The native way (Activity Monitor across tabs)

Open Activity Monitor and click through the tabs:

• CPU tab — sort by %CPU, look for anything sustained above 50%
• Memory tab — check the Memory Pressure graph; yellow or red means swap
• Disk tab — sort by Bytes Written, watch for runaway writers
• Network tab — sort by Sent Bytes/sec, see if something’s uploading

For thermal throttling, you’d separately run pmset -g thermlog in Terminal. For swap usage, sysctl vm.swapusage tells you how much is on disk.

This works — Activity Monitor is genuinely capable software. The honest downside is that you’re context-switching between five views, and the bottleneck can move while you’re looking somewhere else.

The Beacon way

Beacon’s whole reason to exist is showing all of these at once. The menu bar acts as a dashboard, and clicking gives you the detail.

1. Install Beacon and enable the four core readouts: CPU, Memory, Disk, Network in Settings > Menu Bar.
2. Next time the Mac feels slow, glance up. Whatever number is unusually high is the bottleneck.
3. If CPU is high — click it to see the top processes.
4. If memory pressure is yellow/red — same thing; close the worst memory user.
5. If disk I/O is pinned but CPU and memory are calm — that's usually Spotlight reindexing or Time Machine. Wait it out, or click Disk to see what's writing.
6. If everything looks calm but the Mac still feels slow — check Temperature. Thermal throttling will make a healthy-looking system feel terrible.

That sixth point catches more people than they’d expect. A MacBook on a soft surface, a hot room, an Intel Mac with dust in the vents — the chip throttles, every benchmark looks fine, and the machine just feels off. Having temperature in the bar makes that diagnosis a one-second thing.