Speed up macOS High Sierra

Get a snappier, better-performing system with these macOS settings tweaks. Carrie Marshall and Alex Summersby explain how.

Have you updated to High Sierra but found that your Mac now seems sluggish? Or perhaps you haven’t taken the step but want to be sure the latest macOS won’t slow you down. Either way, there’s good news: High Sierra can take a little beddingin, but it is designed to optimise your Mac’s performance, not the opposite, and once you get to grips with it, your Mac could fly.

On older Macs, two changes will make an enormous, life-changing difference: doubling the RAM and replacing the hard disk with an SSD. However, that’s not always practical, affordable, or in some cases even possible — but that doesn’t mean you can’t speed up your Mac.

The principle is straightforward. The more your Mac is having to do, the slower it’ll become. So the trick is to find the things it doesn’t need to do and stop it doing them. That might mean removing unnecessary eye candy or apps you don’t really need, cutting down on what iCloud does in the background, or making sure your Mac isn’t struggling for space.

The macOS Activity Monitor, which lives in Applications > Utilities, is handy here. It enables you to see if an app or even a web process has gone rogue, demanding too much CPU time or memory, and to shut it down. But make sure your Mac isn’t the victim of something else. Often, what appears to be a slow app actually turns out to be a slow or flaky data connection.

So here are some tips for identifying what’s slowing your Mac and fixing it fast, so you can continue doing what you need to unhindered.

“The more it is having to do, the slower it’ll become.”