Why is photoanalysisd using so much CPU on my Mac?

What photoanalysisd is

Type man photoanalysisd in Terminal for Apple’s description: the photo library analysis agent, which handles background processing of photo libraries for Memories, People and scene or object based search.

Apple’s Photos privacy page says this analysis happens on your Mac and includes scene classification, people and pets identification, photo quality analysis and audio classification. It powers Memories, the People & Pets album, Featured Photos and Sharing Suggestions, and Apple says it doesn’t access your photos or videos. When you name a person, Apple says the name and face appear in Photos across all your iCloud-enabled devices.

Two related processes often sit next to it in Activity Monitor. Their manual pages describe photolibraryd as the photo library agent that handles all photo library requests, and cloudphotod as the iCloud Photos agent, responsible for all iCloud Photos activity.

When it runs, and why it’s busy now

Apple doesn’t publish when photoanalysisd runs. Apple’s Photos guide for macOS Monterey says that when you first open Photos, it scans your library to identify people, and that photos you import later are matched against the people you’ve already named. So the busy times are the ones with lots of new photos to look at:

• A big import from a camera, a phone or another library.
• A new Mac, or a library moved over with Migration Assistant.
• Turning on iCloud Photos on a Mac, so the whole library downloads and gets analyzed.

The Eclectic Light Company, which documents macOS background tasks, says photoanalysisd is unlikely to run on battery alone and can keep the efficiency cores of an Apple silicon laptop busy when it’s left connected to power. So expect it to be busiest while a MacBook is plugged in. It also notes that the analysis feeds Spotlight, so mds and mdworker can get busy right after.

The one-minute check

1. Open Activity Monitor (it’s in Applications, Utilities), click CPU and type photo in the search field to see photoanalysisd and photolibraryd together.
2. If you use iCloud Photos, open Photos, select Library in the sidebar, click All Photos and scroll to the bottom. Apple says that’s where the library status shows, including uploads and pauses.
3. Watch it for a few minutes. Steady CPU from photoanalysisd with nothing else busy is the analysis at work, not a fault.

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

What to do

Let it finish

Leave the Mac plugged in, awake and online, overnight if the library is big. Apple gives the same advice for iCloud Photos: connect to power and Wi-Fi and let the device sync uninterrupted overnight, since a large library can take that long. Apple doesn’t give a time for analysis; it depends on how many photos and videos there are.

If iCloud Photos is paused

Apple lists the reasons syncing pauses: Low Power Mode or Low Data Mode, a battery below 20 percent, protecting the device from overheating, and pauses to improve power, performance or the network connection. The status at the bottom of All Photos says which, and Apple says you can click Sync Now or wait a few minutes for it to resume.

If it never seems to finish

Restart, install any further updates in System Settings, General, Software Update, and give it another night on power. Apple advises not to turn iCloud Photos off to fix syncing, because that restarts the syncing process.

If the Mac gets hot

Hours of analysis can warm a MacBook and spin up the fans, and a fanless MacBook Air slows down instead. If it gets hot enough, macOS holds the busy processes back and kernel_task rises in the CPU list. See What is kernel_task? and Why is my Mac so hot?

What not to do

• Don’t force quit photoanalysisd. It’s a macOS agent, not an app you started. Quitting it doesn’t cancel the backlog; the work is still there next time it runs.
• Don’t turn iCloud Photos off and on. Apple says that restarts syncing, which means more downloading and more analysis.
• Don’t buy a “CPU fix” app. This is Photos doing work you’ll use: People, Memories and search.

Keep an eye on it from the menu bar

Activity Monitor names photoanalysisd once you open it. Multimeter keeps the totals in the menu bar, so you can tell whether the Mac is still catching up without opening anything:

• CPU: total use across all cores, every 3 seconds on power and about every 6 on battery. The Sparkline face shows the last few minutes, so you can see the CPU climb while you’re away and settle when the backlog is done. Yellow above 70%, red above 90% by default.
• Thermal pressure: Nominal, Fair, Serious or Critical, the state macOS uses to decide when to hold performance back. It’s a state, not degrees.
• Network speed: total download or upload across Wi-Fi and Ethernet, one direction per meter. A steady upload while iCloud Photos sends a new batch shows up here.

Multimeter shows totals, not per-process lists, so it won’t tell you the CPU is photoanalysisd; Activity Monitor does that. Five live meters use about 3% CPU, and they pause while the displays sleep.