Cleaning the computer's fans is important
Recently, I noticed that my CPU's idle temperatures are around 60 celsius. That's pretty high for an idle state. During busy states such as compilations, the temperatures rose to 90 and the computer slowed down because Intel makes sure that the CPU stops until the temperature goes below a certian threshold.

Disturbed by the fact my computer will die in a few weeks' time if I don't do something about it, I took the liberty to take apart the fans. The CPU's fan had hugh amount of dirt between itself and the processor. I did not realize how much dirt was there until I took it apart. The case's big fan was sluggished and didn't rotate at all when the computer was turned on.

I cleaned and oiled the fans, then replaced them back to their places.

End result is that now the idle temperature is around 37 celsius, and even 30 celsius if I turn the air condition on. The busy state temperature doesn't get above 50.

The case's front leds are not fading anymore.

The CPU's temperature now appears on my KDE's panel so next time I'll take care of these stuff sooner.