Mac fixes: How to pinpoint problems with Activity Monitor

Published in

MacFormat

3 min readJan 9, 2019

By Adam Banks

Computers are complex things and though you’ll have heard the phrase ‘it just works’ in relation to Apple kit many times, it — like any hardware or software — will surely run into trouble at some point.

When something goes wrong, it’s tempting to book an appointment at a Genius Bar to get it sorted out, but that’s not always feasible. The good news is that many Mac problems can be fixed yourself. Apple even provides software tools to help you diagnose them. Here’s how to use Activity Monitor to hone in on software-based slowdowns.

1. Open Activity Monitor

Activity Monitor is included with macOS. It’s in Utilities in the Applications folder. The quickest way to open it is using Spotlight: press Cmd+[spacebar], start typing ‘activity’ and when the app is listed, select it and press Return.

2. See what’s going on

All the currently running processes are listed at the left. Some of these are app names that you’ll recognise (with their icons), others are system functions that you won’t. To see only apps, choose View > Windowed Processes.

3. Check resource usage

The tabs across the top show which processes are using which resources. If the hard disk is constantly chuntering, for example, see Disk. Click the Process Name column to alphabetise processes, or another to rank by usage.

4. It’s down to CPU

To check what’s slowing down your Mac right now, click the CPU tab and rank by % CPU. If ‘nsurlstoraged’ turns out to be a busy little bee, that’s Safari. Close any pages you don’t need open, or quit Safari, and see the percentage fall.

5. All systems go

Don’t be surprised that obscure system processes use resources, but if one seems excessive, search Google for its name to get tips. Processes beginning ‘md’ (for ‘metadata’) relate to Spotlight activity. Consider limiting it in System Preferences’.

6. Kernel blip

If ‘kernel_task’ is using a lot of CPU, it may be managing the processor to stop it overheating under load. If no other processes are using much CPU, reset the SMC (see http://bit.ly/mfrstsmc). If it still happens, there could be a hardware fault.

This content originally appeared in Become an Apple Genius (MacFormat #330, October 2019), available in print here and as an in-app purchase in MacFormat’s iPhone and iPad app. Or, subscribe to MacFormat here.