Activity Monitor on the Apple Mac is a useful utility for seeing what is going on under the macOS user interface, but it is too demanding of resources. Here is a lightweight alternative.
Is the CPU busy? Is memory or disk space running short? Which apps are using the most CPU and RAM? Why is a file taking so long to download? Is it the network speed? What is the time remaining on a MacBook’s battery?
There are many questions you might need the answer to when using your Mac and Activity Monitor can answer all of them. You can easily see technical information like CPU, memory, disk, network and even energy (battery) usage.
There is no doubt that Activity Monitor is a great app, but it is not one that you would want to leave running on the desktop all day because it demands a lot of system resources. The app itself uses a lot of CPU, memory and energy. Run it and check the tabs to see for yourself.
This is most noticeable with older iMacs and MacBooks that have less powerful CPUs, less memory and ageing batteries than with brand new Macs. If your Mac is a few years old, the demands placed on the system by Activity Monitor and the latest version of macOS are too great.
On my MacBook Air, which is around three years old, Activity Monitor averages around 24% CPU activity, sometimes going a bit higher, sometimes a bit lower. Its energy usage is also high and this causes faster battery drain. I run it, take a quick look at the data and quit as soon as I can.
Alternative to Activity Monitor
Eul is an activity monitor for the Mac that enables you monitor the resources the Mac and apps are using. This free app is different to Activity Monitor in several ways and the most obvious is that it runs in the menu bar rather than in its own window.
Start it and several icons and numeric information appears at the top of the screen on the right. For example, it can show the CPU usage as a percentage and the temperature in degrees (Celcius in my case, but probably Fahrenheit in the US). Following the second icon is the memory used and free, memory temperature and percentage used.
There is a fan icon and fan speed, network or internet upload and download speeds, battery percentage and time remaining. This is all very useful information and you can see system stats at a glance. However, there is so much more to see by clicking anywhere in this menu bar display, more than will fit on my MacBook screen.
There are several sections and the first shows CPU usage. There are some basic stats and this is followed by a list of the apps using the most CPU. Look at the screenshot above and notice tat Activity Monitor is 21.4 and eul is 5.2. That is a big difference, but it is often greater as Activity Monitor is frequently 24% to 25%.
A bit further down the panel is the memory usage. There is a summary followed by a list of apps and services using the most memory. Notice that Activity Monitor is 49 MB and that eul is too small to make this list. It uses around 18 MB of memory, which is significantly less.
Eul does not display the full list of running apps and services in either the CPU or memory sections, just the worst offenders. Activity Monitor has more information here, but is it worth it? Eul shows what you need.
See more system information
In some areas, the eul activity monitor shows more information than Apple’s Activity Monitor and here is the battery section of the drop-down menu bar panel. It shows the battery health percentage, maximum and current charge capacities, cycle count, condition and more. It is all important data.
It shows more information in other areas too and you can see the fan speeds and temperatures of components that are not normally visible elsewhere in macOS.
Configure what you want to see
The information that is displayed in the menu bar and in the drop-down panel can be configured. You can choose what to show and anything you are not interested in can be excluded. Here are just a few of the options in the app’s preferences.
The menu bar components can be selected and the order in which they appear can be set. With some items there are several display options and with CPU for example, a mini graph can be included which shows the CPU activity over the last minute or so. The GPU and memory displays can show a similar activity history graph. CPU, GPU and memory can all show the current temperature if you want to keep an eye on whether the Mac is getting too hot.
When you need to see everything that is going on in macOS, use Activity Monitor. However, you usually just want to see the top apps using the most CPU and memory and eul does that using fewer system resources. It is light enough to keep running all the time and the menu bar information makes it easy to keep an eye on what is happening. This is a great free app for the Mac.