How to speed up a slow Mac

As we explained above, adding more RAM isn’t the solution it used to be because upgrading the RAM in modern Macs – especially ones with an M-series chip is impossible.

However, if you own an older Mac – especially if you have a 27-inch iMac – it is relatively easy to upgrade the RAM.

In the past adding more RAM was the go-to solution for improving a Mac’s performance. Before you go ahead and spend money, however, it’s worth trying to figure out how much of a difference it will really make, if any.

The easiest way to do this is to fire up Activity Monitor (it’s in Applications/Utilities), click on the Memory tab and keep an eye on the memory pressure gauge at the bottom of the window. If it’s permanently green, you’re probably not going to see a huge difference by upgrading. If it turns red regularly, it’s worth the expenditure.

How much RAM you add and how you add it is dependent on your Mac. But as a rule of thumb, the effort of performing the installation compared with the marginal cost of bigger RAM modules means that it’s worth maxing out your Mac’s RAM in one go.

That will often mean removing the existing modules and replacing them. It’s a good idea, though not essential, to buy all the RAM you fit at the same time from the same manufacturer. If you decide just to fill empty slots, the same applies. And you should pair RAM modules of the same capacity, if possible.

The biggest hurdle will be whether it is possible to upgrade the RAM in your Mac, it’s easy to add more RAM to a 27-inch iMac, but as we said above, many modern Macs cannot be user-upgraded at all, which is why our usual advice is to buy as much RAM as you can afford as a build-to-order option when you first buy your Mac.

We have a separate tutorial with more information about installing RAM in a Mac.