Observe the Mac for 5 to 10 minutes while the slowdown is happening. Investigate when the same app keeps using CPU, memory pressure stays yellow or red, startup-disk space is low, or disk activity remains busy. If the numbers recover quickly, record the event instead of immediately quitting a process.
Check in this order
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1
Confirm the slowdown is happening
Note when it started, which apps were open, and what you saw: typing delay, slow window switching, a beachball, sustained fan activity, or an intentionally heavy task. A temporary slowdown during indexing, photo analysis, or an update is different from a persistent problem.
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2
See whether one source keeps using CPU
A spike may only be an app launch or page render. A process that remains near the top for several minutes while the slowdown continues is useful evidence. Save your work and quit through the app first; do not stop a system process merely because its name is unfamiliar.
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3
Use memory pressure, not only percent used
macOS uses otherwise idle memory for caching, so high used memory is not automatically a problem. Watch whether memory pressure stays elevated, swap keeps growing, and one app's usage continuously increases.
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4
Check free space on the startup disk
When free space is scarce, updates, caches, swap, and app temporary files have less room to work. Check System Settings → General → Storage, then look for large files, downloads, old installers, and unused apps.
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5
Reproduce after restart, then check login items and updates
A restart clears stale work but is not a diagnosis. If the problem returns, record the reproduction steps and review recently added login items, extensions, and app updates one at a time.
How to use CoreRobin
Run Check now first. A finding appears only after the signal persists and meets stable conditions, rather than turning every changing metric into a task.
Open process trees, CPU, memory, disk activity, and trends when you need evidence. Search and stable sorting help confirm whether the same source persists.
Apple's Activity Monitor also separates system, user, and idle CPU activity and uses memory pressure, swap, and cache together when interpreting memory. Apple CPU guide · Apple memory guide
Prefer reversible actions
- Save your work, quit the app normally, and see whether the problem clears.
- Close unneeded heavy tabs, virtual machines, builds, or sync tasks.
- Free startup-disk space without deleting system folders or unfamiliar caches at random.
- For an unresponsive third-party app, verify its name and path before stopping it; CoreRobin asks for confirmation before acting.
When to investigate further
If the slowdown reliably returns after restart, comes with unexpected restarts or display corruption, affects every app, or persists in safe mode, do not focus on one process alone. Back up important data, install available macOS updates, and use Apple Diagnostics or Apple Support to rule out hardware issues.