how to find source of high data usage

[strawbale]

This evening I see, for the first time, continuous high data usage (>10 Mbps) even with no apps using data according to Activity monitor's Network tab. Using 12.7.2
How can I (quickly) find out what's happening, as I'm always on mobile data.
I’ve got automatic updates set at off.

 

[strawbale]

PS: not just in my user account, but also when in the administrator account

 

[Bigwaff]

In Activity Monitor, select menu View > All Processes. Activity Monitor shows totals .. it sounds like you are more interested in what is happening at the moment, i.e. which process is sending network packets right now. You might need a different system monitoring app. There are a lot to choose from. I use iStat Menus.

 

[strawbale]

 

[strawbale]

As you can see, just now this morning after start up, Firefox only received 3.8MB whilst the data download continues to be >10Mbps (17.3Mbps the moment I took the screenshot). So basically, apart from Firefox none of the other apps used any data, so it must be something else 🤷‍♂️
Would iStat be able to fond the cause/culprit?

 

[strawbale]

Found the same problem om my wife’s Mac.
So using my phone (with its own simcard) for now.

 

[bogdanw]

Maybe it's similar to this "Unwanted Monterey keeps downloading"
https://forums.macrumors.com/threads/unwanted-monterey-keeps-downloading.2333929/
Try from Terminal to see if it's partially downloaded

sudo find /var/folders -iname '*InstallAssistant.pkg*'

 

[strawbale]

Thank you, will try.

 

[strawbale]

In the end I think it was (on both my recent Macs) downloading MacOS updates. On both downloading stopped around 7GB, so must have download a bit yesterday. Will install on one of them, has to be done one day anyway, and check if starts installing immediately.
When I looked at System Preferences > Software Updates the 'Download new updates when available' was ticked, although it never has been like that before (afaik).

Update: it started installing straight away, so must have already downloaded 14.2.1 (8.59GB) beforehand.