Monitor Mac performance, temperature, fan speeds and more

If you want to know why your Mac is running slowly, whether it is running cool or overheating, when it is downloading or uploading, or apps are stressing the CPU, use this system monitor.

Of course, macOS comes with a built-in system monitor and Activity Monitor in the Applications/Utilities folder tells you what is happening behind the scenes inside your Mac. It shows things like the CPU, memory, disk and network usage in figures and charts.

However, there are several problems with Activity Monitor and one is that it takes up a large portion of a MacBook’s screen, especially if you have a 13 in model. It isn’t a problem on an iMac with a big screen of course.

Another issue with Activity Monitor is that it uses too much CPU and on my old MacBook Air it hovers around 16 to 19% CPU with a two-second update interval. That is far too much on a MacBook running on the battery when you are trying to make it last all day.

Lastly, the Mac is packed with temperature sensors and one is on every major component, but Activity Monitor does not show them.

There are alternative utilities to Activity Monitor and iStatistica is a great one. It is not free, but it costs only slightly more than a coffee at your favorite take-away at $4.99. It can be downloaded and tested for free (iStatistica website or Mac App Store), which is what I am doing, but you only get a few days trial.

Monitor the Mac on the menu bar

iStatistica system monitoring app for the Apple Mac

iStatistica works in two different modes and it can be a menu bar extra or a straightforward app with its own window. Here is the menu bar version:

Click the icon and the panel stretches to the bottom of the screen on a MacBook and you need to scroll it to see all the items. However, the information is presented in modules and they can be switched around so the most useful ones are at the top. Modules you don’t need to see can be hidden to shorten the panel.

The menu bar version has another trick and it is able to display live information in the menu. Each item is optional, but you can show the memory usage, CPU usage, free disk space, and temperature.

iStatistica system monitoring app for the Apple Mac

This means that you can keep an eye on key system indicators without opening the panel. It only needs to be opened if you want more detailed information.

Mac monitoring software on the desktop

iStatistica system monitoring app for the Apple Mac

Switch to desktop mode in preferences and all the monitoring modules are displayed in a window on the desktop. There is a summary view, memory, disks, network, processor, battery, Bluetooth and sensors.

Some modules can be expanded to show more information. For example, the Memory and Processor modules show a chart of recent usage, but clicking Show applications lists the apps using the most CPU and RAM. This makes it easy to spot problems, such as an app using too much through a fault or bug.

This display is live and constantly updated. There is no option to set the update speed, but it seems to change every two seconds, which is fine. Unlike Activity Monitor, iStatistica uses less than 1% CPU when the main window is hidden, either minimized or in menu bar mode. This is excellent and it will have little effect on a MacBook battery.

Monitor Mac temperature

iStatistica temperature and fan display on the Apple Mac

A sensors module has to be downloaded and installed to monitor the Mac temperature sensors and monitor the Mac fan speed. Once added, you can enable notifications and an overheating warning, such as when the temperature rises above a certain level.

The module is added to the menu bar panel and desktop window and it shows all the temperature sensors inside the Mac, 15 in my case, plus the fan speed. Temperature can be in F or C and it can also be shown in the menu bar.

The sensors module adds another 1% CPU, so there is a total of around 2% CPU usage on my old and low powered MacBook Air. It is likely to be much less on a new Mac with more powerful hardware. This is excellent compared to Activity Monitor’s 16 to 18% on my Mac (probably less on a brand-new Mac).

Monitor a Mac remotely

Remotely monitor an Apple Mac with iStatistica

There is one more trick that is unexpected, but a brilliant idea and you can monitor your Mac remotely. After enabling the feature in the preferences, any computer, phone or tablet on the local network can be used to monitor the Mac by going to the IP address given.

Here I opened Safari on my iPhone and connected to my MacBook. All the modules and all the information available on the Mac is displayed in the browser. I can see exactly how hard it is working, whether it is idle, whether an app is using too much CPU or RAM and so on.

This could be useful for monitoring your own Mac, for example, if you set it performing some video or audio processing task that takes a long time. It could be used to monitor someone else’s Mac, like a child’s and making sure it is not using too much CPU or RAM, and not overheating playing games.


This is an excellent utility for people that want to monitor the Mac’s resources, performance, temperature and so on. I like it in menu bar mode with the system resources showing. It makes it easy to see when the Mac is working hard or idle, accessing the internet and how fast, and see the current temperature.

iStatistica is recommended.

More Mac utilities:

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