How Processor Speed Is Reported to a Computer

The System tool in Control Panel uses Current Speed to do its reporting rather than Max Speed, but the System tool may display the wrong clock speed for the Central Processing Unit (CPU).

As of January 2002, Windows XP uses the Current Speed value rather than the Max Speed value because the Max Speed value was reporting inconsistent values.

After startup, the processor may not correctly reflect its correct speed until a program utilizes processor cycles.

The computer basic input/output system (BIOS) in some laptop computers may throttle the processor because of heat, load, power AC/DC.

To check the Current Speed setting:

1.Click Start, click Control Panel, and then click Performance and Maintenance.

2.Click See basic information about your computer. On the General tab, the processor speed (in MHz) appears under Computer.

To check the Max Speed setting:

1.Click Start, point to All Programs, point to Accessories, point to System Tools, and then click System Information.

2.The speed (Max Speed) of the processor appears in MHz in the System Information window, in the right column of System Summary, under Processor..

NOTE: System Information from Administrative Tools always reports Max Speed.

If you click Start, point to All Programs, point to Accessories, point to System Tools, and then click System Information, the correct processor speed (for example, 797 MHz = 800 MHz) is shown. After you start the System Information tool, the System Properties tool in Control Panel displays the correct speed. However, when you first start your computer, the incorrect speed is shown in the System Properties tool in Control Panel.