Monitor system resources from the menu bar in macOS Mojave

If your Mac is running slowly, you want to know why and adding MenuMeters to the menu bar enables you to monitor system resources at a glance. See CPU, memory, internet and other stats.

How soon after starting your Mac can you begin to use it? Is it slow to start up first thing in a morning? What is it doing?

At the end of the day, is it OK to turn off or restart or is the Mac still doing important processing or disk tasks?

MacOS often works hard behind the scenes on a variety of tasks, but you would never know because rarely is any indication displayed on the screen. You just don't know what is happening behind the scenes. It is therefore useful to keep an eye on what it is doing and you can easily add activity monitors to the right side of the menu bar at the top of the screen that show CPU usage, memory used and free, internet or LAN activity, and disk usage.

You can see at a glance if the Mac is busy doing something.

There are several apps that provide live system information indicators in the macOS menu bar, but an old favorite of mine is MenuMeters.

It is not the most comprehensive utility of its type and it does not have the most features, but there are a couple of reasons why you might prefer it to more modern alternatives. One is that it is free and open source - how can you not like the price? The other is that is lightweight and uses very little memory or processing power. So little in fact, that you won’t notice it. Typically it uses around 0.6% CPU on my old Mac according to Activity Monitor.

Compatibility with Mojave

The original version of MenuMeters was compatible with OS X up to Mavericks and it did not work from from OS X 10.11 El Capitan onwards. If you have a really old Mac running a very old version of OS X, then go ahead and get it. It has a great display of resource usage in the menu bar.

I had to abandon it from El Capitan onwards, but someone has tweaked the code and made it compatible with modern versions of macOS, including Mojave. Here is it running on Mojave with the dark theme selected and a few of the optional features enabled in its settings. The features have changed very little and it just works on Mojave now.

Install MenuMeters on macOS Mojave

If you are running any recent version of macOS, go and get the new version of MenuMeters. Double click the zip file to extract it and a file called MenuMeters.prefPane appears. Double click it t install it.

System Preferences opens and a message appears saying that it must be installed. When given a choice of installing something for yourself or for all users, it is usually best to install it just for yourself. Click Install.

Because this file was not downloaded from the Mac App Store, a warning message is displayed. I checked it out at the VirusTotal website, which is always recommended, and it was given a clean bill of health, so go ahead and click Open.

Configure the menu bar information display

MenuMeters appears as an extra item at the bottom of the System Preferences window. This is where it is configured. Click it to open it.

MenuMeters adds up to four optional items to the menu bar: CPU, disk, memory and network. Each of these is configurable and you can choose from several different display styles depending on how much information you want to see. You can see two examples of these optional indicators in the screenshots above. For example, with the CPU indicator you can choose a percentage, a graph, a graph and percentage, a thermometer, a percentage and thermometer, a graph and thermometer, or graph, percentage and thermometer.

The other items, disk, memory and network, also have numerous display options. Some of them require more menu bar space than is available on small screens and you might be forced to choose the most compact display options on a smaller MacBook for instance, but you can display more information on a MacBook Pro with a 15in screen and there is obviously more than enough menu bar space on an iMac with a big screen to choose any options you like.

The colours of each item in the menu bar can be changed. The defaults work fine with the traditional light macOS interface, but are too dark for the dark theme. Select a colour at the bottom and it can be changed though. I selected lighter colours to make them easier to see with the dark theme.

Monitor Mac activity

The menu bar display indicators instantly tell you how hard the Mac is working behind the scenes. They show whether the disk is being written to or read from, how hard the processor cores are working, the internet transmit and receive speed when data is being downloaded or uploaded, and so on.

This is all valuable information and it tells you what you Mac is doing when there is nothing obvious happening on the screen. One way of using this information is to wait for the CPU, disk and network activity to zero before shutting down the Mac. Then you can be sure that it has finished doing whatever it needs to and you are not force quitting something that is essential.

It is interesting to watch the Mac start up too, and for a minute or two after the desktop appears, you can see that behind the scenes the Mac is still working hard with high disk, CPU and network activity. That’s why the Mac is slow for a minute or two after switching on if you try to use it. Let it settle down.

Sometimes the Mac slows to a crawl and it is caused by a misbehaving app that is running the CPU at 100%, using the disk excessively, or using far too much memory. This can be seen in the menu bar indicators and is obvious when something is wrong, but without them you might be scratching your head wondering why your Mac is suddenly so slow.

Get more information

Each of the indicators int he menu bar can be clicked to display a menu that provides detailed information. For example, the memory indicator shows memory usage, memory pages, virtual memory usage and swap file usage. The network indicator shows upload and download totals, and so on. Click the CPU and it shows uptime, tasks/threads, the top CPU intensive processes and so on.

Grab a copy of the new MenuMeters that works with Mojave and keep an eye on your Mac’s activity.