Using a system monitor app on the iPhone to see system resource usage like CPU activity, RAM and storage used is a bit geeky, but interesting. See how stressed your phone is by apps and iOS.
There are built-in resource monitors for macOS, Windows and Linux so you can see CPU activity, memory and storage usage, network activity and so on, so why not have one for your iPhone?
They are a bit of a geek tool, but if you want to know what is happening behind the scenes in iOS, there are some apps for those that are interested and know enough about how tech to understand what they are showing.
One problem with trying to monitor CPU activity is that the iPhone puts apps to sleep when you switch away from them to your monitoring app. However, some show the last few seconds or minutes, so you can at least see some data.
Interpreting memory usage is not easy and modern operating systems use them in a variety of ways. You could say that free memory is wasted memory and it is best to put memory to use, such as with caching recently run apps or recent data, rather than leave it idle.
For this reason, free memory is often very low, which isn’t necessarily a bad thing, so don’t use these tools and freak out because there is only a few megabytes of RAM left. That is intentional.
Memory usage also seems partly open to interpretation. It’s use is more complicated than you might think and apps or data may be held in memory in case they are needed again. Is this free memory or used memory? Technically, it is used, but could be made free in an instant if needed. For this reason, the apps sometimes show different memory usage figures.
Device Info iMonitor
Price: Free | By: Artem Tselikov | Size: 27.5 MB | iOS: 10.0 or later
Device Info iMonitor has not been updated for over two years, but with one feature exception, it still works fine and I ran it on iOS 10.13.5 on an iPhone 11.
The home screen shows three displays – the Central Processor Unit, Random-access Memory and Disk Space. These are live and update every second or two. The CPU mostly idles when the app is on the screen, but the chart shows usage over time, so you can start another app, switch to Device Info iMonitor and see how much the CPU was being taxed over the previous half minute or so.
The memory display shows the free, wired, active and inactive usage. Free and inactive are the total free memory and wired and active represent memory in use. Disk Space shows the amount of phone storage used and free. This can be seen in Settings of course, but it is still useful to include it as part of the system information here.
The Network tab shows cellular and Wi-Fi usage, showing the amount of data uploaded and downloaded. Device shows some basic information about the device like iOS version, screen resolution, uptime and so on.
This is a free app with no ads and the Battery tab does not work. However, there is useful information on the other tabs and it is presented in an easy-to-ready display.
Sys Activity Manager
Price: Free | By: Sohel Mazumder | Size: 20.4 MB | iOS: 8.0 or later
Sys Activity Manager looks fantastic and the home screen is very nice indeed. It was updated as recently as last year, but some information displayed on my iPhone 11 and iOS 13.5 is wrong.
The home screen display showing the memory usage with the total, wired, active, inactive and free space is OK. It basically categorize everything not wired, active or inactive as free. The Battery screen shows estimated usage times on the remaining juice, which seem OK.
However, the Disk screen shows completely wrong figures and it is clueless as to how much storage is in the iPhone and how much is used or free. The Network tab has some incorrect data, too.
This app worked best on my old iPhone 6 with iOS 12, but not perfectly on my iPhone 11 with iOS 13. It needs an update, but some information is useful and it is quite nice to look at.
iStatistica
Price: Free | By: Andrey Tsarkov | Size: 4.5 MB | iOS: 8.0 or later
I looked at iStatistica for the Apple Mac and found it to be an excellent system monitor for macOS. There is also an iStatistica app for the iPhone and it is equally good. It is free and works well in basic mode, but there is an Expert mode that costs only US $0.99 or UK £0.99 and it displays a bit more information.
There are dark and light themes and it is just a one-screen app. However, it contains everything you need to know.
Across the top is Memory, Processor and Storage usage and these live displays show in numbers and graphic, how much is being used and how much is free.
The memory display shows the total, free, used, cache and wired memory. The storage shows the free, used and total space on the phone.
The battery section shows the current charge percentage and gives estimates of the time remaining. The network section is useful and it shows the device IP address on the local Wi-Fi network, the router IP address and your public IP address. The current upload and download speed and total data transferred is shown.
All of the information on this screen is also available as a Today screen widget, so you can see the resource usage without having to open the app. This could be useful, but I would like to see an update, it has been over two years since the last one.
System Util Dashboard Lite
Price: Free | By: Sohel Mazumder | Size: 29.6 MB | iOS: 8.0 or later
System Util Dashboard Lite was updated only recently, but even so, it does not appear to be fully compatible with the iPhone 11 and iOS 13. Most, but not all features work. and it works better on older iPhones and iOS versions.
Tap each of these tiles and they go to a new screen with more detailed information. Memory for example, shows a pie chart of usage, active, inactive wired and free memory.
The disk display is just plain wrong and it said the iPhone 11 had 0.01 GB of total storage. There is missing information in the Network section, which is likely a permissions issue. However, it does show your Wi-Fi IP address and the amount of data sent and received over Wi-Fi and cellular.
The app is useful on older phones, but less so with new phones with the latest iOS. It only needs a minor compatibility update and then it would be a great app. I would like to see a different color scheme as I found it hard to read some text.
System Information Lite
Price: Free | By: Kenneth Ackerson | Size: 14.2 MB | iOS: 10.0 or later
System Information Lite is free, but System Information full app is just US $0.99. The free and full apps are almost identical and paying just removes the small ad at the bottom of the screen and adds themes, so you can go dark if you prefer it.
This is a one-screen app and it is nearly all text. It is visually dull, but the information displayed is useful and comprehensive. The display is live and there are mini pie charts next to the disk, CPU and memory displays.
In the RAM section is physical memory, wired, active, inactive, other, and free. It also shows the page file activity and some is always present, but excessive amounts could indicate that iOS is running short of memory.
The CPU section shows the current CPU used and idle figures and while it does not show a history chart, it does show the most recent three average load figures. The network section shows the local Wi-Fi IP address and the external public IP address.
This is a simple app that shows useful information for anyone wanting to view and monitor resources on the iPhone.
System Status: hw monitor
Price: Free | By: Techet | Size: 7.4 MB | iOS: 13.3 or later
At last, an up to date system monitor! System Status is a free app that enables you to monitor some system resources in the iPhone and it is designed for the latest iPhones and iOS. It is a feature-limited app in its free version and System Status Pro, costing $3.99, is required for full monitoring.
I tried the free version and it does a good job of showing CPU and storage usage. It shows how hard the CPU is working in a live bar and in figures below, and it shows the previous CPU use 1, 5 and 15 minutes ago.
The network information is comprehensive and it shows the router (gateway) IP address, the iPhone’s public IP address through Wi-Fi and cellular connections (they are different), the network type connected to, local device IP address, DNS server addresses and more. It has everything you need to know.
You need the Pro version to get a display of memory usage and see active charts of resource usage. The free app is good, but limited.
Conclusion
It is quite clear that access to system information has changed in recent versions of iOS and old apps either display some wrong information or no information on the latest iPhone and iOS version. It is probably a permissions issue, so is fixable if the developers could find time to update the apps.
They all work very well on older iPhones and iOS versions, but some need an update to fully work with the iPhone 11 and iOS 13 and later. They mostly work, but with some missing information.
System Status is the best here, but you need the Pro version to see everything and view charts. The free version is a bit limited. System Information Lite has comprehensive resource usage information for free, but iStatistica is visually more exciting.
