i dun remember.... This multiplier will decrease because I use the laptop without using a fan cooler?
Well check. If the CPU is overheating, it will throttle itself. Notebook CPUs have higher heat tolerances than desktop CPUs though so it would have to hit like 90-100C or more to throttle. I'm not sure of the temps specific to your CPU model though.
And what do you mean "without a fan cooler"? Are you saying you removed the CPU fan?