A lot of people say that it's hard for a CPU to get failed. I experience that too. My CPU bought 9 years ago , everything else replaced but it still serves.
I still wonder if a CPU will still fail some time and what's the primary reason
CPUs rarely fail. Typically the computer becomes obsolete before the CPU fails. The usual cause is old age. The internal structures of the CPU deteriorate and eventually something fails and the CPU ceases to function. This is inevitable for all man made devices. How long that will take is essentially unknowable but many CPUs are 30 and more years old and still working. Many die earlier for a wide variety of reasons. Modern CPUs haven't been around long enough for meaningful statistics.
CPUs, as with all man made devices, do deteriorate with age. The second law of thermodynamics with it's corollaries dictates that this must be. At some point a CPU will die. But this usually is of no practical concern. This deterioration does not effect performance. Digital electronics doesn't work that way. The CPU will work at full speed until the moment of failure. Not that you are likely to see that.
As for turning the PC off or leaving it run all the time being best for reliability: This has been discussed for decades and there are strongly help opinions on both sides. As long as you keep the temperatures in check and avoid abuse how long a PC will last is determined more by quality of manufacture and luck that by anything you can do.
Larry, look at the Youtube video about the Apollo AGM that was restored. Solid state and still works with minor repairs. Software and creating the “Man in the Middle” hardware was the hardest part. Proves that Tech may age but can still work after decades.
I am well aware of how long electronic devices can last. I have no argument with that. My point was simply that such devices do deteriorate with age and at some point will fail. I have plenty of experience with that.
Your CPU should be fine provide the PC's cooling is adequate - clean out the dust once per year. There is a very slim chance of a very high energy cosmic ray blowing a transistor on the chip!
A friend of mine is still using a 386 computer to run his wood saw mill every day, 7 days a week, still works as new although everything around it was changed several times. Every now and then he blows out about a pound of dust from it so CPU overheat doesn't set wood dust on fire although it smoldered few times.
Quote