How t o Pinpoint p roblems u sing A ctivity Monitor

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.

2 See what’s going on

All the currently running processes are listed on the left. Some of these are app names that you’ll recognize (with their icons), others are system functions 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 alphabetize processes, or another to rank by usage.

4 It’s down to CPU

To check what’s currently slowing down your Mac, click the CPU tab and rank by percent CPU. If you find that ‘nsurlstoraged’ is being overworked, close any Safari pages you don’t need, or quit the app, and see the percentage fall.

5 All systems go

It isn’t surprising to see obscure system processes use resources, but if any seem excessive, search it in Google to get tips. Processes beginning ‘md’ relate to Spotlight activity. To consider limiting it see page 26.

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 use much CPU, reset the SMC (see page 22). If it still happens, it’s likely a hardware fault.