Cursor Performance after long tasks or writing files

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Hey, both issues are known bugs. Quick summary:

  1. UI freezes when the agent writes files: we’re seeing this for a few users. It’s related to how the renderer handles file operations.

  2. Slowdown in long sessions: you’re right about the root cause. There’s a memory leak in the renderer, so long chats with code blocks keep accumulating memory. Users are seeing the renderer process at 3+ GB, with spikes up to 30 GB.

Related thread with diagnostics: Cursor UI freezes up when agent is working

For now, the workaround is to periodically close long chats and start new ones. That should reset the renderer’s accumulated memory.

You can also check a couple things for diagnostics:

  1. Ctrl + Shift + P > Developer: Open Process Explorer: check the memory usage of the “window” process during freezes.
  2. Help > Toggle Developer Tools > Console: see if there are warnings like ListenerLeak or MaxListenersExceededWarning.

The team is aware of both issues, and your report helps with prioritization. Let me know if closing chats helps.