Why is softwareupdated using so much CPU on my Mac?

What softwareupdated is

Type man softwareupdated in Terminal for Apple’s description: the macOS Software Update daemon, the main daemon responsible for running software updates. It does the work behind the Software Update pane in System Settings and the softwareupdate command.

Apple says Software Update finds, downloads and installs Apple software updates that are compatible with your Mac. With Download new updates when available turned on in its Automatic Updates options, macOS downloads updates in the background without asking, so softwareupdated can get busy while you’re doing something else.

What Preparing means

Apple names three stages, downloading, preparing and installing, but doesn’t say in its support pages what preparing involves. The Eclectic Light Company, which read the logs of a macOS 26.4 update, reports that during preparation softwareupdated verifies the downloaded parts of the update and prepares the system volume, then stages everything for the restart. That work shows up as high CPU from softwareupdated or related processes plus disk activity in Activity Monitor.

The same report says the time remaining isn’t reliable near the end: on its Mac, a 5 minute estimate took over 12 minutes, then the bar sat at the same percent for almost 12 more before jumping ahead. Its advice is to wait unless there’s a real sign of failure, since nothing you do makes an update finish faster. These details are secondary, not from Apple.

The one-minute check

1. Open System Settings, click General, then Software Update. Apple says it shows the installed version of macOS and whether an update is available, with Update Now or, for a downloaded update, Update Tonight.
2. In Activity Monitor (Applications, Utilities), click CPU and type update in the search field. softwareupdated near the top while Software Update shows a download or Preparing is the update at work.
3. In Terminal, softwareupdate --list lists available updates without needing an admin password, according to its manual page.

% CPU counts each core as 100%, so it can read over 100% on a Mac with several cores.

What to do

Let it finish, plugged in and online

Keep the Mac awake, on power and connected. Apple says the installer needs a stable internet connection to download macOS and to get firmware and information specific to your Mac. During installation, Apple says to let it finish without putting the Mac to sleep or closing the lid, and that the Mac may restart and show a progress bar or a blank screen several times. Back up first; see Why is backupd using so much CPU? for Time Machine.

Pick a better time

Once an update has downloaded, Apple says Update Tonight installs it overnight, as long as the Mac is on, plugged in and online. If you’d rather choose when downloads happen, click the Info button next to Automatic Updates and turn off Download new updates when available.

If there isn’t enough space

If Software Update says there isn’t enough storage, Apple says to free up space and try again. See Why is my Mac storage full?

If it stops with an error

Apple says errors while downloading, preparing or installing are sometimes temporary. Check that Apple’s System Status page shows macOS Software Update as available, check your connection and try again. Apple also says that starting up in safe mode before installing from Software Update may help.

Afterward, other processes take a turn

After an update, Apple says Spotlight re-indexes, which can take hours or even days. That’s mds_stores, and image analysis as mediaanalysisd, not Software Update. See Why are mds_stores and mdworker using so much CPU? and Why is mediaanalysisd using so much CPU?

What not to do

• Don’t force quit softwareupdated. It’s a macOS daemon; quitting it interrupts the download or preparation, and the work starts again later.
• Don’t close the lid or let the Mac sleep during installation. Apple asks you to let it finish.
• Don’t give up on a stuck-looking time remaining too soon. High CPU or disk activity from softwareupdated means it’s still working.

Keep an eye on it from the menu bar

Software Update shows the status when you open it. Multimeter keeps the totals in the menu bar all the time:

• Network speed: total download or upload per second across Wi-Fi and Ethernet, one direction per meter. A big steady download while Software Update shows a download in progress is the update coming in; when it drops back, the download is done.
• CPU: total use across all cores, every 3 seconds on power and about every 6 on battery. Yellow above 70%, red above 90% by default. CPU that stays up after the download ends, while Software Update shows Preparing, is the preparing stage.
• Disk space: how full the startup disk is, warning at 85% full and critical at 95%, so you know before an update runs short of room.
• Thermal pressure: Nominal, Fair, Serious or Critical, the state macOS uses to decide when to hold performance back. It’s a state, not degrees.

Multimeter’s built-in meters show totals for the whole Mac, not processes, so they won’t say the CPU is softwareupdated. If you want the name too, the Busiest process recipe is a Script meter that shows the top process name and its % CPU; it keeps the first 14 characters, so this one shows as softwareupdate. Five live meters use about 3% CPU, and they pause while the displays sleep.