MacOS has a monitoring hub called Activity Monitor, a snapshot of everything that’s currently happening on your Mac. We’ve discussed how you can use Activity Monitor to examine what background apps are running and how to improve performance if something goes wrong. Now let’s dive a little deeper by taking a closer look at your Mac’s memory, and specifically what “swapping used” memory is all about – and how it can help you spot problems like memory leaks.
What is swap used for?
Open Activity Monitor on your Mac (you can find it in the Utilities folder) and you’ll see a wealth of information broken down into major categories including CPU, Memory, Power, and Disk. The Memory tab, in particular, shows how much RAM you’re using and what’s occupying that RAM. Below is a summary window showing basic statistics including total physical memory, how much memory is being used, recent cached files. and something called “Swap Used”.
If you were curious and searched for “swap used,” you might have found Apple’s official description: “The amount of space used on your startup disk to move unused files in and out of RAM.” That’s close, but doesn’t offer much meaning for those studying their Mac’s RAM.
Swap space is a type of memory that computers use to offload current memory requirements. The operating system does this by borrowing some space from somewhere else – in this case the startup disk – and using it to temporarily store some data while the RAM is busy with other tasks.
Is using swap a bad thing?
Traditionally, the swap used has a bad reputation as it can indicate RAM issues. Swap space is more likely to be used when your current memory isn’t enough to efficiently do all the tasks you’re trying to do on macOS. It tends to get higher when you have many apps or tabs open at the same time or trying to manage other complex processes.
However, swap used doesn’t always mean something is wrong. This is an indicator of potential problems, but some swap space usage is not uncommon. In fact, macOS in Mavericks and Yosemite has received major memory updates that have adjusted the way memory is allocated to make RAM usage more efficient. Today, at least one swap is expected to be used to indicate that space has been reserved on the boot disk in case it is needed. You can even have several GB of swap space occupied and not notice anything because RAM is allocated to the most important tasks.
Is your swap used in the danger zone?
So if the “Swap used” section doesn’t necessarily indicate a problem, how can you tell if your Mac has memory issues? It’s important to consider several factors here to get a clearer picture of how your memory is doing. This includes considerations such as:
- Your accumulator pressure diagram is no longer in the green zone: The handy little graph next to the macOS memory stats window shows how much RAM is currently in use. As long as this graphic stays green, you should be in the clear. If the chart gets too high, it will turn yellow and then red, indicating that you have some memory issues and should try cutting down some unnecessary or background apps.
- Your Mac freezes or crashes frequently: If the apps you use start freezing or keep crashing, you could be taxing your Mac’s memory beyond what it can handle. This is a sign to bring up the activity monitor and look out for signs that you need to reduce app activity, including high swap usage and the memory graph in the red.
- You are using a memory intensive program like a Windows VM: Although it is possible to run them, complex programs like this put a heavy load on macOS. It’s a good idea to check your memory stats the first time you run complex software and make sure your RAM is appropriate for your tasks.
- Your total used swap space suddenly starts to spike: If your swap space is consistently a few GB or so, you probably don’t need to worry. However, if it suddenly spikes to much higher levels for no apparent reason, it could be a sign of a problem, especially if your computer crashes shortly after.
Can I upgrade RAM in a Mac?
Not often, no. While the cure for RAM issues can often be an upgrade to more RAM, that’s not a solution that works for Macs. For example, most of the latest generation MacBooks have RAM soldered directly to the motherboard. iMacs tend to be a bit luckier in this regard – some may have empty slots to add more memory, although Apple wants you to use its own techs. You can go to yours About this Mac section on MacOS and select the memory Tab to see if there are any empty slots left.
In the meantime, we have a guide to freeing up Mac storage with better control over how you use apps, as well as other tricks that might help if your swap usage looks alarming.