What the memory gauge in NotchStar shows
The memory ring in NotchStar shows active, wired and compressed memory as a share of your Mac’s total memory. It does not count cached files, which macOS fills spare memory with and gives back when an app needs it.
What goes into the number
Each second NotchStar reads three counters from macOS and multiplies them by the memory page size:
- Active memory, which apps are using now or used very recently.
- Wired memory. Apple describes this as memory the system needs to operate, which cannot be cached or compressed.
- Compressed memory. Apple says macOS compresses memory to free up RAM as the Mac nears its memory limit.
The total is divided by your Mac’s installed memory and capped at 100 percent. Cached files are left out on purpose, so a Mac that has simply been on for days does not look full.
Colours
The ring turns orange above 65 percent and red above 85 percent.
Why it may differ from Activity Monitor
Activity Monitor has its own Memory Used figure, and it also shows a Memory Pressure graph that Apple says depends on free memory, swap rate, wired memory and file cached memory. The two numbers can disagree because they add different things up. Use the ring for a glance and Activity Monitor when you need the detail. A comparison of the two lists what each one shows.
For the full tool, read the System stats feature page. If the CPU ring is the one you want, read what the CPU gauge shows.
