You may use the About This Mac window and Process Viewer to check the amount of installed RAM and the amount of memory being used.

Viewing the Amount of RAM (Physical Memory) Installed

1. Choose About This Mac from the Apple Menu.
2. The Memory field specifies the amount of RAM installed in the computer.

1. Open ProcessViewer (located at /Applications/Utilities/).
2. Mac OS X processes and applications are listed in the Process Viewer window. The right-hand column, "% Memory," indicates the current percentage of available RAM that is in use by an application or process.

1. It is normal for some processes to use very little RAM at times, such as 0.0% or 0.1%.
2. It is normal for a process' memory usage to change dramatically from one sample period to another, depending on how you are using your computer.
3. Not all applications have an easily-recognizable name in the Process Listing window. For example: Microsoft Internet Explorer 5.1 may appear as "LaunchCFMApp." This is normal.
4. Classic applications do not appear individually in the Process Listing window. The Classic environment appears as a single process (TruBlueEnvironme). This is normal.
5. ProcessViewer itself is listed because it is a running application. This is normal.

1. Open Terminal (located at /Applications/Utilities/).
2. Type: top
3. Press Return to open the top utility in the Terminal window. Two rows near the top of the window, "PhysMem:" and "VM:" indicate overall physical RAM and virtual memory usage, respectively. The two columns on the right, "RSIZE" and "VSIZE" offer memory usage information per application. RSIZE indicates the amount of physical RAM in use by the application or process, in megabytes ("M") or kilobytes ("K"). VSIZE indicates the amount of virtual memory Mac OS X has assigned for this process or application, in megabytes ("M") or gigabytes ("G").
4. When you are finished reviewing the information, press the Q key to exit top.

1. Application and process names are listed in the "COMMAND" column.
2. It is normal for some processes to use very little RAM, such as 64K.
3. Not all applications may have an easily-recognizable name in the Terminal window. For example: Microsoft Internet Explorer 5.1 appears as "Internet E."
4. As with Process Viewer, Classic applications do not appear individually in the Process Listing window. It is normal for the Classic environment to appear as a single process (TruBlueEnv).
5. top itself is listed because it is a running application. This is normal.