CPU fan is main part of any computer. CPU fan is connected to CPU heatsink and works to move heat away from CPU. The speed of CPU fan is mainly what decides temperature of CPU. By knowing CPU fan speed, you can make changes to CPU fan to either decrease the noise created by fan or reduce temperature of CPU. There two various methods to decide existing CPU fan speed, one using system BIOS and one using free software.

Instructions

Determining the CPU Fan Speed through the System BIOS

1. Step 1

Restart PC.

2. Step 2

Enter the command to access BIOS as system starts boot process.

3. Step 3

Choose sector having power use or hardware checking information. CPU fan speed is usually placed in one of these sections. Read BIOS documentation if you are unable to get CPU fan speed.
Determining the CPU Fan Speed Using SpeedFan

Step 1

Download and install SpeedFan.

Step 2

Run SpeedFan.

Step 3

Choose "Charts" tab.

Step 4

Choose "fan speeds" to show and examine CPU fan speed.