View memory usage in Activity Monitor on Mac

In the Activity Monitor app on your Mac, click Memory to see the following in the bottom of the window:

• Memory Pressure: Graphically represents how efficiently your memory is serving your processing needs.

  Memory pressure is determined by the amount of free memory, swap rate, wired memory and file cached memory.

• Physical Memory: The app could not be installed.

• Memory Used: The app could not be installed. To the right, you can see where the memory is allocated.

  • App Memory: The app could not be installed.

  • Wired Memory: Memory required by the system to operate. This memory can’t be cached and must stay in RAM, so it’s not available to other apps.

  • Compressed: The amount of memory that has been compressed to make more RAM available.

    When your computer approaches its maximum memory capacity, inactive apps in memory are compressed, making more memory available to active apps. Select the Compressed Memory column, then look in the VM Compressed column for each app to see the amount of memory being compressed for that app.

• Cached Files: Size of files cached by the system into unused memory to improve performance.

  Until this memory is overwritten, it remains cached, so it can help improve performance when you reopen the app.

• Swap Used: The amount of space being used on your startup disk to swap unused files to and from RAM.

To display more columns, choose View > Columns, then choose the columns you want to show.