How do I check fan speed on my Macbook Air?

[Charioteer]

I wanted to know the fan speed of my MacBookAir. because i think my machine is working slowly, and also my browser is opens slowly and also taking long time for the closing the window. I closed all the applications then also it is very hot and noisy. I have checked into the utilities and activity but it did not mention anything. If anyone having any knowledge on this then please reply me.

[Hardwareman]

You can check the your fan speed on your system, I was also wanted to check my fan speed and managed it to the constant value, then i downloaded SMCfan which is specially use for Mac. The main feature of this is that not only you can see the fan speed but also you can fix it to the constant value you want. you can also check the temperature of you CPU. I recommend you to get it to your computer. I hope this information may help you.

[Maxforu]

As you have written in the question that your CPU is getting hot and noisy, i think this is due to the temperature is reaches to the critical point of your MacBookAir. I advice you when this happen put your machine to the sleep and then again wake it after 7-8 second, i think by doing this your machine will come on the normal point.

[Killen]

There is a freeware application named CoreDuoTemp which is use to operate CPU temperature with the indicators for displaying CPU frequencies, usage of CPU with the multiple temperature units like °F, °C or K. CoreDuoTemp is the one of the most usable application for the Mac OS X. There is a few graphical user interface utility use for the MacBookAir users to adjust and control the fan cooler. You can also speedup your fan to make Mac machine cooler at low temperature.

[T.J.]

A software CoolBook use to check and maintain all your fan speed after installing this software to your computer, launch it and then at the left corner there is a adapter button click on it and then your processors throttle steps list will display. I advice you when you are doing the testing process close all your important data because if the voltage is low then there is possibilities of kernel panic. If you are having any other query then please reply me.