Find rogue apps slowing down your Mac

Does your Mac feel slower than it used to be? Norman Bean helps you track down the culprits.

All computers slow down over time, for a whole variety of reasons. In recent issues of APC, we’ve shown you how to address some of these reasons, decluttering your Mac to detox it, for example (APC #447), and speeding up performance on old Macs by switching to the free and open-source elementary OS (APC #442). In an upcoming issue, we’ll tackle some common causes of slowdowns in High Sierra, particularly those relating to preferences and the configuration of your system. But first, let’s look at probably the most common cause of poor performance in any version of macOS: your apps.

Don’t panic! Of course, the whole point of having a computer is to do things with it. But when your Mac seems sluggish, this is often because of apps running in the background, putting an unnecessary load on the CPU or hogging too much memory. If your Mac seems to be taking an eon to start up, this is often because unneeded apps or utilities are loading.

We’ll show you how to use your Mac’s built-in Activity Monitor to identify such rogue apps, and a handy utility called KnockKnock to find apps that persistently install at startup. Persistent installation is a typical characteristic of malware, but it’s important to note that not all such apps are malware, and KnockKnock will check the apps it finds for you. Either way, of course, you probably don’t need them!

One word of advice: occasionally, we recommend utilities for specific tasks (like KnockKnock here), but you should avoid installing general ‘cleanup’ apps, particularly those promoted in pop-up ads on the web. Few, if any, such apps are updated for the latest versions of macOS, and they usually do more harm than good, hogging resources in the background themselves, or worse.