com.apple.Safari.History CPU Usage

Hello jeffrva,

If I'm understanding you right, the process called "com.apple.Safari.History" is using a high percentage of your Mac CPU capability and you would like to know how to prevent it from doing so.

It sounds like you've done a great job in narrowing this down to being related to Safari syncing with iCloud. I have some steps I'd like you to try that may help resolve what you're experiencing. I recommend checking to see what difference each step takes on that specific process in Activity Monitor.

1. Install any available updates for macOS Catalina, and install all software updates available in the Mac App Store. Also install all third-party software and plug-in updates.
2. Clear Safari history: Safari > Clear History.
3. Empty safari cashes: Safari > Develop > Empty Caches. If you don't the Develop option, you can enable it with these steps: Safari > Preferences, click Advanced, then select “Show Develop menu in menu bar.”
4. Quit the Safari application and restart your Mac.
5. Boot into safe mode and check Activity Monitor there. Restart your Mac like normal to leave safe mode afterwards.

Respond back if you continue to experience the same issue. Let me know if you saw the same high usage for that Activity Monitor process while booted in safe mode. Also, let me know what percentages you see for System and User for CPU. If you're unsure where to get that information, this support article should help: How to use Activity Monitor on your Mac.

Thanks for using Apple Support Communities.

Take care.