Reminders (remindd) waste CPU resources 100% / 200%, and obviously drain batteries of my MacBook Pro, Apple Watch (guess) and iPhone (guess)
A couple of months ago I decided to get a new MacBook Pro, it felt like the battery on the old one was dying, same applies to my old iPhone. And here I am, with a new MacBook (Intel, i9), new iPhone and Apple Watch. The laptop dies within 1-2 hours without external power. The Apple Watch dies within 5 hours. And the fresh iPhone dies within 12 hours.
After a little bit of checking, I realised that something weird is going on with Reminders. On the laptop, it is remindd process that constantly consumes 200% / two cores of CPU. By the moment, I have been too lazy to find a way to check what is going on with the iPhone and Watch, but I suppose it is the same issue, remindd. I would have assumed the implementation of the service should be the same, or very similar across all the devices. Including bugs.
I am not taking the ultimately hopeless path of reporting that to Apple, but instead, I am just trying to get rid of all the reminders, everywhere. Which seems to be impossible. Even after creating a little shortcut (Shortcuts app on iOS) and deleting all of them, notifications still appear.
So how can I remove them all?
I'm on Big Sur and have had the same problem for months. Finally decided to reboot reminders the hard way.
- Disable reminders in Settings > Accounts > iCloud
- Use Activity Monitor to force quit
remindd - Quit the Reminders application if you have it open.
- Use Terminal to
rm -rf ~/Library/Reminders - Use Activity Monitor to force quit
reminddagain, just in case. - Re-enable reminders in Settings > Accounts > iCloud
- Watch CPU spike up again for a while...
So none of that worked. The remindd process came back and continued churning a sqlite database in the ~/Library/Reminders/ folder to over 300MB in size.
Ultimately, I deleted all the reminders on my iPhone, iPad, and mac. I transferred them into a different list manager. Then I deleted the app from those devices, turned off iCloud syncing for reminders, quit the reminders app on my iMac, et voila, the remindd process on my iMac self-terminated and stopped eating my CPU.
I now wonder if this was part of the background battery drain on my iPhone.