Messages in the Cloud eats my M1 MBP (Sonoma)

Since being forced to upgrade to Sonoma (Ventura 13.6.1 totally bricked my M1 MBP), IMDPersistenceAgent, imagent and cloudd run constantly at 35 - 105 %CPU. Unchecking Messages Prefs>Messages in the Cloud stops 'em cold, but what am I losing?

You lose the synchronization of iMessages across all your devices. You didn’t say how long the processes had been running at higher than normal levels, but it’s not unusual for synchronization/propagation activities to run at a higher than normal level for even several days after a major OS update. Apple also notes about this particular feature “When you first turn on Messages in iCloud, it may take some time for all of them to appear on each device.”


First noticed it two or three days ago. I’ll let them run over the weekend and revisit the thread next week. Thanks Jeff~

Received a new M2 Pro mini three days ago and upgraded it from Ventura to current Sonoma after restoring from a backup of the Mac it replaced. On the day after, I did see several messages on it. But yesterday and this morning I did not see a couple of 2FA authorization codes, and had to get them from my iPhone.

Messages > Settings > iMessages shows that I’m signed in, and “Enable Messages in iCloud” is checked, but the Sync Now button is disabled. I tried Sign Out and back in to no avail. IMDPersistenceAgent, imagent and cloudd all show CPU Time greater than an hour, but 0.0 %CPU now.

On my system, Messages usually seems to understand which iCloud-connected device is active – and notifies that device first when new Messages arrive. Other devices signed into the same iCloud account also receive the message but might not pop a notification. IMDPersistenceAgent, cloudd and imagent all play parts in the sync dance and are always present on the CPU list. But unless there’s data to sync, they’re asleep; OTOH, tons of unsync’d Message data on a new Mac seems to take a long time to sync up (mine needed 1wk+).

Thanks, but… 1wk+ ? :astonished:

Half a gig of Messages data…

Jut out of curiosity, on your phone do you have Settings / Messages / Text message forwarding set to the Mac? That should deliver the 2FA text messages to the Mac (as opposed to waiting for the sync to finish.)

Besides signing out of the Apple ID and signing in again on the Mac (which can be a pain in the neck), I can’t think of any other troubleshooting (other than perhaps creating a new account on the Mac and building that account from scratch - also a huge pain.)

Of course there is always the call to AppleCare to see what they say.