Fix High CPU Usage and Slow Performance from OneDrive on Mac
Question details
The user needs to resolve an issue where their Mac experiences severe performance degradation and continuous fan noise due to high CPU usage from the OneDrive client.
- Product
- OneDrive for Mac
- Device & OS
- macOS (Catalina 10.15.7)
- Scenario
- Synchronizing personal OneDrive storage alongside multiple SharePoint sites with the Files On-Demand feature enabled.
- Observed behavior
- The Mac computer becomes noticeably slow and unresponsive, and the internal cooling fans run constantly due to high processing loads generated by the sync client.
Before troubleshooting, open the Activity Monitor on your Mac to confirm that OneDrive is the specific process causing the high CPU usage, and ensure you have a stable internet connection to prevent sync loops.
Test with Fewer SharePoint Libraries
Reducing the number of actively synchronized SharePoint sites helps identify if a specific library's size or contents are overloading the OneDrive sync engine.
When you sync multiple massive SharePoint sites simultaneously, the OneDrive client has to constantly check for changes across thousands of files. This indexing process can heavily tax a Mac's CPU. Isolating the libraries can help pinpoint the exact source of the performance drop.
Click the OneDrive cloud icon in the Mac menu bar at the top of your screen, click the gear icon for 'Help & Settings', and select 'Preferences'.
Navigate to the 'Account' tab. You will see a list of all syncing locations. Click 'Stop sync' next to your connected SharePoint libraries.
Open Activity Monitor and observe the OneDrive process. If the CPU usage drops significantly, begin re-adding your SharePoint libraries one by one to find out which specific site is causing the high load.
Downgrade to an Earlier Version of OneDrive
If the performance issue started recently and affects multiple Macs on the same network, rolling back to a previous stable build of OneDrive can bypass current software bugs.
Experience Lightweight Document Management with WPS Office
If OneDrive and heavy Office applications are slowing down your Mac and causing high CPU usage, switch to WPS Office. It provides a lightweight, highly optimized alternative that handles your documents smoothly without draining your Mac's processing power.
- 1. Download and Install: Get the free WPS Office application for Mac from the official website and install it quickly.
- 2. Open Office Files: Double-click your existing Microsoft Office documents to open them effortlessly in WPS Office.
- 3. Work Without Lag: Enjoy editing and formatting your documents with a lightweight app that keeps your Mac's fan quiet.
Frequently Asked Questions
Why does OneDrive Files On-Demand cause high CPU on Mac?
Files On-Demand constantly checks file states between the cloud and your local Mac storage. When syncing multiple large SharePoint sites, this continuous indexing and metadata checking process can heavily consume Mac CPU resources, leading to slow performance.
Can I disable OneDrive sync for specific folders to save CPU?
Yes. Open OneDrive Preferences, navigate to the Account tab, click 'Choose Folders' next to your syncing locations, and uncheck large folders you don't need local access to. This reduces the amount of data the client has to index.
How do I check if OneDrive is the exact cause of my Mac's slow performance?
Open the Activity Monitor on your Mac (you can find it via Spotlight search). Click on the 'CPU' tab and look for the 'OneDrive' process in the list. If its % CPU is consistently high (e.g., above 90%), it is likely the cause of your performance issues.
Will pausing OneDrive sync stop my Mac fan from running constantly?
Yes. Clicking the OneDrive icon in the menu bar and selecting 'Pause Syncing' will temporarily halt the indexing process. If the fan noise stops and CPU usage drops, it confirms that the sync client is the root cause of the heavy processing load.
