MacFix
Performance
If your Mac feels slow, hot, or loud under load — and Activity Monitor's own numbers don't add up to what you'd expect — you're in the right cluster.
Symptom → article
| What you're seeing | Article |
|---|---|
| kernel_task is using 300%+ CPU by itself | kernel_task using high CPU on Apple Silicon |
| Fans are stuck at max speed and the case is hot even when idle-ish | Mac fan running loud and stuck at max (thermal throttling) |
| Everything feels slower for a while right after updating macOS | Mac running slow after a macOS update |
| WindowServer itself is the process using high CPU | WindowServer using high CPU on Apple Silicon |
| Wondering if Rosetta is why a specific app feels slow | Does Rosetta 2 slow down apps on Apple Silicon? |