CPUPeek

The question it answers: what is making my Mac slow or hot right now?

What you see

• Three rings: thermal state (Normal to Critical, as macOS reports it), CPU in use (apps and macOS), and the load average against your number of cores.
• A chart of CPU use since you opened the screen, and one bar per core.
• Details: user, system and idle time, the chip, its performance and efficiency cores, and uptime.
• Average load over 1, 5 and 15 minutes.
• Using the most CPU: the 20 busiest processes over the last interval. 100 % is one core fully busy, as in Activity Monitor, so a busy app can show more than 100 %.

The launcher shows a CPU ring with CPU in use and the load average. It turns red, with “running hot”, when macOS reports a high thermal state. It takes two readings a third of a second apart when the popover opens; nothing keeps running.

How to use it

1. Open CPUPeek. Values appear almost at once and then refresh at the interval set in Settings (1 to 10 seconds).
2. Reproduce the slowdown and watch the busiest processes and the thermal ring. Open ProcessPeek to inspect a process.
3. Leave the screen and sampling stops.

Good to know

• The thermal ring is the state macOS reports, not a temperature. macOS has no public way to read the CPU temperature or frequency without administrator rights, so CPUPeek shows neither.
• Other users’ and protected processes, including some macOS services, are not listed. Overall and per-core use always include them.
• There is no GPU reading yet.

Privacy

Read-only; nothing is stored or sent. It needs no permission. See permissions.