MacOS has a monitoring center called Activity Monitor, a snapshot of everything that’s happening on your Mac right now. We discussed how to use activity monitor to learn what background apps are working and how you can improve performance when things aren’t going well. Now we’re going to dig a little deeper, take a look at your Mac’s memory, and specifically what “used” memory is—and how it can will help you detect problems such as memory leaks.
What is a swap used for?
Open Activity Monitor on your Mac (you can find it in Communal services folder) and you’ll see tons of information divided into major categories including CPU, Memory, Power, and Disk. The Memory tab specifically shows how much AZP you are using and what RAM is occupied. At the bottom, you will see a summary window that shows basic statistics, including total physical memory, amount of memory used, current cached files. and what is called “swap used”.
If you got curious and looked up “swap used”, you may have found Apple’s official description: “The amount of space used on your boot disk to swap unused files to and from RAM.” It’s short, but it doesn’t matter much to anyone learning about their Mac’s RAM.
Paging memory is a type of memory that computers use to offload their current RAM. The operating system does this by borrowing space from somewhere else—in this case, the boot disk—and using it to temporarily store some data while RAM is busy doing other tasks.
Is using swap a bad thing?
Traditionally, the swap used has a bad reputation as it can indicate problems with RAM. Paging memory will most often be used when the current memory is not enough to efficiently handle all the tasks you are trying to do in MacOS. It tends to be higher when you have many programs or tabs open at the same time, or when you’re trying to manage other complex processes.
However, using a swap doesn’t always mean something is wrong. This is an indicator of potential problems, but some use of swap memory is not uncommon. In fact, MacOS received major memory updates in Mavericks and Yosemite that adjusted the way memory was allocated to make RAM usage more efficient. These days, using swap is expected, at a minimum, to indicate that startup disk space is reserved in case it’s needed. You can even use a few GB of swap memory and not notice a thing, because the RAM is allocated for the most important tasks.
Is your swap used in a dangerous area?
So, if the “swap used” section doesn’t necessarily indicate a problem, how can you tell if there’s a problem with your Mac’s RAM? Here, it’s important to consider several factors to get a better idea of how your memory works. This includes considerations such as:
- Your memory pressure graph is no longer displayed in green: A handy little graph next to the MacOS Memory Statistics window shows how much RAM is currently in use. As long as this graph remains green, you should be clean. If the graph gets too high, it will turn yellow and then red, indicating that you have memory problems and should cut down on some unnecessary or background programs.
- Your Mac hangs or crashes frequently: If the applications you use start to freeze or crash intermittently, you may be putting more stress on your Mac’s memory than it can handle. This is a sign to open Activity Monitor and watch for signs that you need to reduce application activity, including high swap used and a red memory graph.
- You are using a program that requires a lot of memory, such as a Windows virtual machine: Although they can be run, such complex programs put a heavy load on MacOS. It’s a good idea to check your memory stats when you first start running complex software and make sure your RAM is capable of handling what you’re doing.
- The total amount of paging memory used suddenly starts to grow: If your swap memory is consistently a couple GB or so, you probably have nothing to worry about. But if it suddenly starts rising to much higher levels for no apparent reason, it could be a sign of a problem, especially if your computer crashes soon after.
Can I upgrade the RAM on my Mac?
Not often, no. While the cure for RAM problems can often be to upgrade to more RAM, this is 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 lucky in this regard – some may have empty slots for adding more memory, although Apple will want you to use its own specialists. You can go to yours About this Mac section on MacOS and select Memory to see if there are any empty slots left.
Meanwhile, we have a guide to freeing up mac memory with more control over how you use apps, and other tricks that can help if your swap usage starts to look worrisome.