How Apple silicon CPUs control core frequencies and power use when running in Low Power mode. Includes M4 Pro and M3 Pro data, and estimates of energy requirements.
CPU
Apple refers to Energy Modes and Power Modes, and despite older MacBook Pro models offering Low Power mode, tells us that isn’t what Low Power mode is now. Here are the observations and explanations.
Can you promote threads set to run on E cores so they run on P cores instead? Can you demote threads set to run on cores so they run in the background on E cores?
Originally Process Viewer and CPU Monitor, in 2003 they merged and became Activity Monitor, similar to the current version. Also borrowed for Xcode Instruments.
The CPU view in Activity Monitor is the starting point for tuning the performance of software. Here are its virtues, and a few vices to beware of when using it.
Set up from unboxing in under 2 hours, its CPU cores perform better than those in the M3, differences that are magnified.
One of the most common reasons for opening Activity Monitor is to check the % CPU of processes that might be running out of control. How accurate are those figures, though, and should you believe them?
Is an M4 next week a better risk than the promise of a better model next year? Understand how to select the M4 chip suited to your needs, and specify your new Mac.
Comparing CPU core counts and maximum core frequencies across the four families in the M series, plus expected performance of Thunderbolt 5. Which M4 Mac should you buy?
How could you study how Apple silicon CPU cores are used to run code? Comparisons between Activity Monitor, Xcode Instruments, and powermetrics.
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