Investigating operating system CPU usage

Products

• VMware
• VMware Desktop Hypervisor
• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

This article guides you through determining CPU usage. CPU usage information is useful in addressing problems encountered with an operating system as a result of a process taking up excessive CPU cycles. CPU usage problems result in slow operating system performance.

Resolution

The methods of determining CPU usage differ between operating systems. Refer to the section that matches your operating system.

 

Note: If you determine that you have insufficient CPU, you must limit the amount of concurrently running processes or increase the amount of CPU. If your operating system has been installed on a virtual machine running under an ESX Server host, see Increasing the amount of CPU assigned to a virtual machine (1004060).

If this is a virtual machine, you can increase the amount of memory assigned to the virtual machine. For more information, see Change the Memory Configuration

Windows

To determine CPU usage:

1. Run the Task Manager:
    
   1. Click Start > Run.
   2. Type taskmgr.
   3. Click OK.
   
   Note: If you are running a version of Windows where this command does not work, you must find an alternate method of launching the Task Manager or determining the CPU usage.
    
2. Click the Performance tab. The CPU usage is displayed.
   
   Note: Click the Processes tab to get detailed information about the CPU usage of each process. Click the CPU column to sort the results by the amount of CPU each process is using.

Linux

Note: The exact procedure may differ between distributions of Linux. If the following commands do not work, consult the manual for your distribution of Linux.

 

To determine CPU usage:

1. Open a shell prompt. For more information, see Opening a command or shell prompt (1003892) .
2. Type top and press Enter. The CPU usage is displayed.

Mac OS

To determine CPU usage:

1. Press Shift + Command + U.
2. Double-click Activity Monitor.
3. Click the CPU tab. The CPU usage is displayed.
   
   Note: Click the % CPU column to sort these results by the amount of CPU each process is using.