Chat Feature Causes 130.1% CPU Spike and Unresponsiveness on M3 MacBook Pro

Bug Reports
1

I’m experiencing a severe, ongoing issue with Cursor’s chat feature on my M3 MacBook Pro. The app works perfectly until I use the chat, at which point Cursor spikes to 130.1% CPU (previously 104.2% yesterday) and becomes unresponsive (marked in red in Activity Monitor). This started suddenly yesterday afternoon, despite working fine earlier in the day, and persists this morning even after clearing the cache and waiting overnight.

Details:
• Device: M3 MacBook Pro (likely M3 Pro, 11-12 cores)
• OS: macOS 15.4.1 (24E263)
• Cursor Version: Version: 0.49.6 (Universal), VSCode Version: 1.96.2
• Plan: Pro plan, spending ~$250/month on requests
• Project: 120-file codebase, full-stack development
• Steps to Reproduce: Open Cursor, make any chat request (e.g., “Explain this line”). Cursor immediately spikes to 130.1% CPU and freezes.
• Attempts to Fix:
o Cleared cache (~/Library/Application Support/Cursor/Cache and ~/Library/Application Support/Cursor/Code/Cache).
o Restarted Mac, updated macOS, waited overnight—issue persists.

This issue is severely disrupting my workflow, especially given my heavy reliance on the chat feature for full-stack development. I’ve been using chat all day without issues until this sudden problem, and I’ve never experienced this before.

2

Hey, have you tried opening another project or an empty Cursor window? I think the issue might be related to the large chat history in your project.

3

Thank you Dean. I opened a new project with no issues, that worked, but any new chats in my project with my data does not work. Is there a way to clear out the old chat history? I use Gemini 2.5 Pro, so my chat histories get very big, then I create a new chat and probably have hundreds.

4

You can rename your project or move it to another location on your drive, and this will clear your history.

5

Dean, YOU are a lifesaver. My level of panic was getting high… Hard to operate at 1x pace manually when you have been at 100x pace.

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