Tech Myth - CPU speed decreases over time

Does your CPU's speed decrease over time?

The answer to this question is both NO and YES, but more NO than YES.  Let me explain:

Your CPU (Central Processing Unit) which is also refereed to as the "brains" of your computer system is responsible for doing all the tasks you throw at it and was designed to operate within a certain range of processing speed and temperature.  The more tasks you give the CPU to do the faster it works and naturally the more heat is generated - this, of course will  require more cooling to keep it within its operational temperature range.

Now, once the temperature is properly regulated i.e the CPU is being properly cooled, it will continue working within its processing speed's range for all of its days, which tend to end when you decide to throw it out for a new one and NOT because it "grounded" to a halt.  So it's speed DOES NOT DECREASE.

On the other hand, the thermal paste which lies between the CPU and the cooling system (heat-sink and fan) over time loses its effectiveness (becoming hard, dry and even flaky in some instances), when this happens, if the paste is not replaced, the cooling system gets compromised resulting in the CPU having to run at the lower end of its processing speed range to avoid overheating and possibly destroying itself - this tend to account for the perceived slowing down of the CPU over time even though in truth and fact a CPU's speed IS its speed for all time.

NB:  In most cases the CPU in a computer system will still be fully functional when that system is thrown out.   It's components like the motherboard and other integrated devices that may require a system replacement.  There are times though, when as with all things man-made a CPU will fail, but that's just the result of mass-production and manufacturer's error unless you have a serious motherboard or electrical problem.