There were four basic materials that the Egyptians used to build the pyramids: limestone, pink granite, basalt, and alabaster. Each type of material had a diverse use. Limestone had, for the most part, two uses.
To answer your question: The useful lifespan of a CPU is about 3-4 years. My guess on the technical lifespan under full load is closer to 8-10 years if nothing else breaks and takes the CPU with it. The reasons: High Performance Computing Clusters usually keep the computers for 3-4 years.
As with all technology, there are two main factors that will determine how long it will be of value to you: how well you maintain it and what you want to do with it. If you take good care of a laptop, there's no reason why the physical hardware won't last for 8 to 10 years.s with all technology, there are two main factors that will determine how long it will be of value to you: how well you maintain it and what you want to do with it. If you take good care of a laptop, there's no reason why the physical hardware won't last for 8 to 10 years.