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.
Get Slate in your inbox. Laptops: The typical lifespan of a lithium-ion laptop battery is about 18 months to 2 years, Buchmann says, but yours will last much longer if you don't punish it too much. The main stresses include undercharging, overcharging, and one that few of us consider: heat.